JP2014216128A - Inspection method for battery and manufacturing method for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method for a battery capable of properly discriminating a battery in which foreign matters have not entered in a semi-cylindrical end of an electrode body, and to provide a manufacturing method for a battery in which foreign matters have not entered in a semi-cylindrical end.SOLUTION: An inspection method for a battery 1 which includes: a wound electrode body 10 whose cross-section PJ is an elliptical shape; and a battery case 20 housing the electrode body inside thereof is provided. The electrode body has semi-cylindrical ends 10R located on both ends of an elliptical shape in a major axis direction DM and an intermediate portion 10S located between the semi-cylindrical ends 10R. The inspection method includes: a first compression step for compressing the semi-cylindrical ends in a minor axis direction DN and compressing the electrode body in the major axis direction through the battery case from outside the battery case; a first placing step for placing the battery while the semi-cylindrical ends being compressed in a minor axis direction and the electrode body being compressed in the major axis direction; and a first voltage measuring step for measuring a voltage V between terminals of the battery after the first placing step.

Description

  The present invention relates to a method for inspecting a battery including a wound electrode body having a cross section of an ellipse and a method for manufacturing such a battery.

  In recent years, a chargeable / dischargeable battery has been used as a driving power source for vehicles such as hybrid vehicles and electric vehicles, and portable electronic devices such as notebook computers and video camcorders. As a technique for inspecting such a battery, for example, Patent Document 1 discloses a battery short-circuit inspection method in which a short-circuit inspection is performed in a state where an electrode plate group (electrode body) is compressed. Specifically, this battery short-circuit inspection method uses a pressurizing means for a stacked electrode plate group in which positive and negative plates are alternately stacked via a separator before being inserted into a battery case. Pressurize in the stacking direction. Then, if conductive foreign matter is mixed between the positive electrode plate and the negative electrode plate, the positive electrode plate and the negative electrode plate are short-circuited through the foreign matter by pressurization, so that the foreign matter can be detected. .

JP 2001-236985 A

  However, it is difficult to apply the battery short-circuit inspection method of Patent Document 1 to a battery in which a flat wound electrode body having an oval cross section is accommodated in a battery case. The flat wound electrode body is positioned at both ends in the major axis direction of the elliptical cross section, and the two semi-cylindrical end portions in which the positive electrode plate, the separator and the negative electrode plate are bent into a semi-cylindrical shape, and these The positive electrode plate, the separator, and the negative electrode plate are positioned between the semi-cylindrical ends, and have an intermediate portion in which the ellipse is stacked in the minor axis direction.

Similarly to the description in Patent Document 1, when a flat wound electrode body is pressed through the battery case in the minor axis direction, the portion adjacent to the intermediate portion of the semi-cylindrical end portion is also present together with the intermediate portion. Although the pressure is applied in the minor axis direction, no pressure applied by the pressurizing means is applied to the part outside the major axis direction from this part. That is, only the part adjacent to the intermediate part in the semi-cylindrical end part is compressed. Moreover, the semi-cylindrical end portion is deformed to protrude outward in the major axis direction due to the pressurization, and the pressing force in the minor axis direction applied to the semi-cylindrical end portion is reduced. Not fully compressed in the radial direction.
On the other hand, when a flat wound electrode body is pressed in the major axis direction through the battery case, the semi-cylindrical end part can be compressed only from one direction in the major axis direction. Can not be compressed. In addition, since the major axis direction and the stacking direction of the intermediate portion are orthogonal to each other, the intermediate portion cannot also be sufficiently compressed.
After all, when a flat wound electrode body is pressed in one direction of the minor axis direction or the major axis direction, at least the semi-cylindrical end portion of the electrode body cannot be sufficiently compressed. Even if conductive foreign matter is mixed in the semi-cylindrical end portion, it is difficult to cause a short circuit between the positive and negative electrodes due to the conductive foreign matter at the time of inspection. Therefore, the conductive foreign matter mixed in the semicylindrical end portion may not be detected properly.

  The present invention has been made in view of such a problem, and provides a battery inspection method capable of appropriately discriminating a battery in which a foreign object is not mixed in a semi-cylindrical end portion of an electrode body. Moreover, it aims at providing the manufacturing method of the battery which manufactures the battery in which the foreign material does not mix in a semicylindrical edge part.

  One embodiment of the present invention is a wound electrode body in which a strip-like positive electrode plate, a negative electrode plate, and a separator are wound around a winding axis, and the cross section has an oval shape, and the above electrode body. A battery case housed therein, wherein the electrode bodies are located at both ends of the oblong shape in the major axis direction, and the positive electrode plate, the separator, and the negative electrode plate are half of each other. Located between the semi-cylindrical ends bent into a cylindrical shape and the semi-cylindrical ends, the positive electrode plate, the separator and the negative electrode plate are laminated in the minor axis direction of the oval shape. The semi-cylindrical end of the electrode body from the outside of the battery case through the battery case, respectively, in the minor axis direction, and the electrode body in the major axis direction. A first compression step to compress and the semi-cylindrical end In the state where the electrode body is compressed in the major axis direction while being compressed in the minor axis direction, and after the first stationary step, the inter-terminal voltage of the battery is A first voltage measuring step for measuring a battery.

  The above-described battery inspection method includes the above-described first compression step, first stationary step, and first voltage measurement step. Among these, in the first compression step and the first stationary step, the semi-cylindrical end portion of the electrode body is compressed in the short diameter direction and the electrode body is compressed in the long diameter direction. It can compress from (major axis direction and minor axis direction). In addition, since the electrode body is also compressed in the major axis direction via the battery case, the deformation in which the semi-cylindrical end portion protrudes outward in the major axis direction is suppressed by pressing in the minor axis direction, and the semi-cylindrical end portion is It is possible to sufficiently compress in the minor axis direction and the major axis direction. For this reason, when conductive foreign matter is mixed in the semi-cylindrical end portion, a short circuit between the positive and negative electrodes due to the foreign matter is caused in the semi-cylindrical end portion in the first compression step and the first stationary step. Can do. On the other hand, when no conductive foreign matter is mixed in the semi-cylindrical end portion, no short circuit occurs between the positive and negative electrodes at the semi-cylindrical end portion. It is possible to appropriately determine a battery that is not mixed.

  In the first standing step, a battery in a predetermined charged state (for example, SOC 98%) in a state where the semicylindrical end portion is compressed in the short diameter direction and the electrode body is compressed in the long diameter direction, The process of leaving still in an open state over a predetermined period (for example, 3 days (= 72 hours)) at a predetermined temperature (for example, 25 ° C.) may be mentioned.

  Further, in the above-described battery inspection method, the intermediate portion of the electrode body is inserted through the battery case from the outside of the battery case before the first compression step or after the first voltage measurement step. After the second compression step of compressing in the minor axis direction, the second stationary step of standing the battery in a state where the intermediate portion is compressed in the minor axis direction, and the second stationary step, It is good to set it as the inspection method of a battery provided with the 2nd voltage measurement process which measures the voltage between terminals of a battery.

  The battery inspection method includes the above-described second compression step, second stationary step, and second voltage measurement step before the first compression step or after the first voltage measurement step. For this reason, in addition to the semi-cylindrical end portions in the first compression step and the first stationary step, in the second compression step and the second stationary step, the conductive foreign matter mixed in the intermediate portion causes a gap between the positive and negative electrodes in the intermediate portion. Can cause a short circuit. On the other hand, when no conductive foreign matter is mixed in the intermediate portion, no short circuit occurs in the intermediate portion, so a battery with no foreign matter mixed in the electrode body (semi-cylindrical end portion and intermediate portion) is properly identified. can do.

  As the second stationary step, the battery in which the intermediate portion is compressed in the minor axis direction is opened for a predetermined period under a predetermined charging state and at a predetermined temperature as in the first stationary step. A step of standing still.

  Further, in the above-described battery inspection method, the second compression step, the second stationary step, and the second voltage measurement step may be a battery inspection method that is performed before the first compression step.

By the way, when the intermediate portion is pressurized from the outside during the second compression step (and the second stationary step), the conductive foreign matter mixed in the intermediate portion is transferred from the intermediate portion to the semicylindrical end portion. It has become clear that there is a case to move to.
On the other hand, in the above-described battery inspection method, the second compression step, the second stationary step, and the second voltage measurement step are performed before the first compression step, and therefore, in the second compression step and the second stationary step. Even when the conductive foreign matter moves from the intermediate portion to the semi-cylindrical end portion, it is possible to reliably detect a short circuit caused by the foreign matter in the subsequent first compression step.

  Alternatively, according to another aspect of the present invention, a wound electrode body in which a belt-like positive electrode plate, a negative electrode plate, and a separator are wound around a winding axis, and the cross section has an elliptical shape, A battery case containing the electrode body therein, wherein the electrode bodies are respectively located at both ends of the elliptical major axis direction, the positive plate, the separator, and the negative electrode A semi-cylindrical end portion formed by bending each plate into a semi-cylindrical shape and the semi-cylindrical end portions are positioned between the positive electrode plate, the separator, and the negative electrode plate in the minor axis direction of the elliptical shape. And compressing the semi-cylindrical end of the electrode body in the minor axis direction from the outside of the battery case via the battery case, and the electrode body A first compression step of compressing in the major axis direction; A first stationary step of standing the battery in a state where the cylindrical end portion is compressed in the minor axis direction and the electrode body is compressed in the major axis direction, and the battery after the first stationary step. A first voltage measuring step for measuring a voltage between terminals of the battery.

  The above-described battery manufacturing method includes the first compression step, the first stationary step, and the first voltage measurement step described above. Among these, in the first compression step and the first stationary step, the semi-cylindrical end portion of the electrode body is compressed in the short diameter direction and the electrode body is compressed in the long diameter direction. It can compress from (major axis direction and minor axis direction). In addition, since the electrode body is also compressed in the major axis direction via the battery case, the deformation in which the semi-cylindrical end portion protrudes outward in the major axis direction is suppressed by pressing in the minor axis direction, and the semi-cylindrical end portion is It is possible to sufficiently compress in the minor axis direction and the major axis direction. For this reason, when conductive foreign matter is mixed in the semi-cylindrical end portion, a short circuit between the positive and negative electrodes due to the foreign matter is caused in the semi-cylindrical end portion in the first compression step and the first stationary step. Can do. Therefore, a battery in which no conductive foreign matter is mixed into the semicylindrical end can be manufactured.

  Further, in the battery manufacturing method described above, the intermediate portion of the electrode body is inserted from the outside of the battery case through the battery case before the first compression step or after the first voltage measurement step. After the second compression step of compressing in the minor axis direction, the second stationary step of standing the battery in a state where the intermediate portion is compressed in the minor axis direction, and the second stationary step, It is good to set it as the manufacturing method of a battery provided with the 2nd voltage measurement process which measures the voltage between terminals of a battery.

  The battery manufacturing method includes the above-described second compression step, second stationary step, and second voltage measurement step before the first compression step or after the first voltage measurement step. For this reason, in addition to the semi-cylindrical ends in the first compression step and the first stationary step, in the second compression step and the second stationary step, a short circuit between the positive and negative electrodes due to conductive foreign matter mixed in the intermediate portion is performed. It can be generated in the middle part. Accordingly, it is possible to manufacture a battery in which no conductive foreign matter is mixed into the electrode body (semi-cylindrical end portion and intermediate portion).

  Furthermore, in the battery manufacturing method described above, the second compression step, the second stationary step, and the second voltage measurement step may be a battery manufacturing method that is performed before the first compression step.

  In the battery manufacturing method described above, since the second compression step, the second static step, and the second voltage measurement step are performed before the first compression step, in the second compression step and the second static step, from the intermediate portion Even when the conductive foreign matter moves to the semi-cylindrical end portion, it is possible to reliably cause a short circuit due to the foreign matter in the subsequent first compression step. Therefore, it is possible to reliably manufacture a battery in which no conductive foreign matter is mixed into the electrode body.

It is a partial notch perspective view of the battery of embodiment. It is sectional drawing (AA cross section of FIG. 1) of the battery of embodiment. It is sectional drawing (BB cross section of FIG. 2) of the battery of embodiment. It is a flowchart of the manufacturing method of the battery concerning an embodiment, and the inspection method of a battery. It is explanatory drawing of the manufacturing method of the battery concerning embodiment. It is explanatory drawing of the manufacturing method of the battery concerning embodiment. It is explanatory drawing about the intermediate | middle part compression process among the manufacturing methods of the battery concerning embodiment, and the inspection method of a battery. It is explanatory drawing about an edge part compression process among the manufacturing method of the battery concerning embodiment, and the inspection method of a battery.

(Embodiment)
Next, embodiments of the present invention will be described with reference to the drawings. First, the battery 1 according to the present embodiment will be described. The battery 1 is a lithium ion secondary battery including a flat wound electrode body 10 having an elliptical cross section PJ and a battery case 20 that houses the electrode body 10 (see FIG. 1). In addition to these, the battery 1 is connected to a positive electrode plate 11 (described later) of the electrode body 10 in the battery case 20, and a positive electrode terminal structure 40 partially disposed outside the battery case 20; It has a negative electrode terminal structure 50 that is connected to a negative electrode plate 12 (described later) of the electrode body 10 and a part of which is disposed outside the battery case 20. The first insulating member interposed between the battery case 20 and the positive electrode terminal structure 40 (a positive electrode extending member 41 described later) or the negative electrode terminal structure 50 (a negative electrode extending member 51 described later) in the battery case 20. 70 and a second insulating member 80 disposed on the battery case 20.

  Among these, the first insulating member 70 made of an insulating resin electrically insulates the positive electrode extending member 41 and the sealing lid 26 of the battery case 20, or the negative electrode extending member 51 and the sealing lid 26. In addition, the second insulating member 80 made of the same insulating resin as the first insulating member 70 is the positive electrode terminal structure 40, the positive electrode external terminal 47 and the positive electrode bolt 49 described below, or the negative electrode terminal structure 50. A negative electrode external terminal 57 and a negative electrode bolt 59 described later are electrically insulated from the sealing lid 26.

The positive electrode terminal structure 40 is connected to the positive electrode plate 11 of the electrode body 10 in the battery case 20, and is disposed outside the battery case 20 and a positive electrode extending member 41 that extends through the battery case 20 to the outside. And the positive electrode bolt 49 which is located outside the battery case 20 and is electrically connected to the positive electrode external terminal 47 (see FIG. 2).
Among these, the positive electrode external terminal 47 is formed by forming an aluminum plate material into a crank shape. Further, as shown in FIG. 2, the positive bolt 49 has a configuration in which the shaft portion 49 </ b> C is inserted through the through hole 47 </ b> SH of the positive external terminal 47. Furthermore, the positive electrode extending member 41 includes a pedestal portion 45, a shaft portion 42, a positive electrode connecting portion 44, and a positive electrode caulking portion 43 (see FIG. 2). Among these, the positive electrode crimping portion 43 is connected to the upper end of the shaft portion 42 and is crimped (deformed so as to expand in diameter) to form a disk shape, and is electrically and mechanically connected to the positive electrode external terminal 47. ing. On the other hand, the positive electrode connecting portion 44 extends from the pedestal portion 45 to the case bottom surface 22 side of the battery case 20 and is welded to the positive electrode plate 11 (positive electrode foil 11F) of the electrode body 10.

  Further, the negative electrode terminal structure 50 is connected to the negative electrode plate 12 in the battery case 20, and similarly to the positive electrode terminal structure 40 described above, the negative electrode extending member 51, the negative electrode external terminal 57, and the negative electrode external terminal 57. And a negative electrode bolt 59 electrically connected to (see FIG. 2). As shown in FIG. 2, the negative electrode bolt 59 has a shape in which a shaft portion 59 </ b> C is inserted through a through hole 57 </ b> SH of a negative electrode external terminal 57 formed of a copper plate material in a crank shape. Further, the negative electrode extending member 51 has a pedestal portion 55, a shaft portion 52, a negative electrode connecting portion 54, and a negative electrode caulking portion 53 similar to those on the positive electrode side (see FIG. 2). Among these, the negative electrode crimping portion 53 is electrically and mechanically connected to the negative electrode external terminal 57. Further, the negative electrode connecting portion 54 is welded to the negative electrode plate 12 (negative electrode foil 12F) of the electrode body 10.

  On the other hand, the battery case 20 includes a rectangular bottomed box-shaped battery case body 21 and a rectangular flat plate-shaped sealing lid 26, both of which are made of metal. Among these, the sealing lid 26 closes the opening of the battery case body 21 and is welded to the battery case body 21. The sealing lid 26 has circular through holes 26H and 26H penetrating the sealing lid 26 at both ends in the longitudinal direction (left and right direction in FIG. 2).

  Moreover, the rectangular bottomed box-shaped battery case body 21 has a rectangular case bottom surface 22 that forms the bottom surface of the battery case main body 21 itself. Further, from the long side edge 22 </ b> L of the case bottom surface 22, the two first case wall surfaces 23, 23 rising perpendicularly to the case bottom surface 22, and from the short side edge 22 </ b> S of the case bottom surface 22, the case bottom surface 22. There are two second case wall surfaces 24, 24 that rise vertically.

The electrode body 10 is formed by winding a belt-like positive electrode plate 11 and a negative electrode plate 12 in a flat shape around a winding axis AX via a belt-like separator 13 made of a porous resin, The cross-section PJ is an oblong flat wound electrode body (see FIG. 1). The electrode body 10 is impregnated with an organic electrolytic solution (not shown) containing lithium ions.
The strip-shaped positive electrode plate 11 constituting the electrode body 10 includes a positive electrode foil 11F made of aluminum and a positive electrode active material layer (not shown) including positive electrode active material particles. The strip-shaped negative electrode plate 12 has a negative electrode foil 12F made of copper and a negative electrode active material layer (not shown) containing negative electrode active material particles.

  The electrode body 10 is located at both ends of the ellipse-shaped cross section PJ in the major axis direction DM, and the positive electrode plate 11, the separator 13, and the negative electrode plate 12 are arranged in two semi-cylindrical shapes, respectively. Positioned between the cylindrical end portions 10R and 10R and the two semi-cylindrical end portions 10R and 10R, the positive electrode plate 11, the separator 13 and the negative electrode plate 12 are laminated in the minor axis direction DN of the cross section PJ. And an intermediate portion 10S (see FIGS. 2 and 3). In the intermediate portion 10S, as shown in FIG. 3, a large number of flat plate-like positive electrode plates 11, separators 13 and negative electrode plates 12 are laminated.

Next, a method for manufacturing the battery 1 according to the present embodiment will be described with reference to the drawings. FIG. 4 is a flowchart showing the flow of the manufacturing method of the battery 1 of the present embodiment.
First, in the electrode body manufacturing process of step S1, a strip-shaped separator 13 is interposed between the strip-shaped positive electrode plate 11 and the negative electrode plate 12 which are each manufactured by a known method, and these are wound around the winding axis AX. Turn. After winding, it was compressed and deformed into a flat shape to obtain a flat wound electrode body 10.
Next, in the battery manufacturing step (step S <b> 2), first, the positive electrode terminal structure 40 and the negative electrode terminal structure 50 that are fixedly arranged in advance on the sealing lid 26 are connected to the electrode body 10 described above. Specifically, in the electrode body 10, the positive electrode extending member 41 (positive electrode connecting portion 44) of the positive electrode terminal structure 40 is connected to the positive electrode foil 11 F of the positive electrode plate 11, and the negative electrode terminal is connected to the negative electrode foil 12 F of the negative electrode plate 12. The negative electrode extension member 51 (negative electrode connection part 54) of the structure 50 was joined respectively (refer FIG. 5).
After the electrode body 10 fixed to the sealing lid 26 was inserted into the battery case body 21, the sealing lid 26 and the battery case body 21 arranged so as to cover the opening of the battery case body 21 were joined by laser welding. And after injecting electrolyte solution into the battery case 20 from the injection hole which is not illustrated, the injection hole was sealed and the battery 1 was produced.

Next, the intermediate part compression step (step S3) in the method for manufacturing the battery 1 according to the present embodiment will be described.
In the intermediate portion compression step, with respect to the battery 1 produced in the above-described battery production step, the intermediate portion 10S of the electrode body 10 is passed through the battery case 20 from the outside of the battery case 20 of the battery 1 in the minor axis direction DN (FIG. 7 in the horizontal direction).
In the intermediate portion compression step, an intermediate portion compression device PS that can compress the intermediate portion 10S of the electrode body 10 in the short diameter direction DN through the first case wall surface 23 of the battery case 20 (battery case main body 21) is used (FIG. 7). reference). This intermediate part compression device PS has a pair of compression parts PT, PT that can be compressed with the battery case 20 sandwiched in the short diameter direction DN with respect to the intermediate part 10S (see FIG. 7).

In the intermediate portion compression step, the intermediate portion 10S is moved from the outside of the battery case 20 through the first case wall surface 23 of the battery case 20 to the minor axis direction using the pair of compression portions PT and PT of the intermediate portion compression device PS described above. Put in DN. At this time, the surface pressure applied to the first case wall surface 23 of the battery case 20 by the compression unit PT is set to 1.5 MPa. Thereby, the intermediate part 10S of the electrode body 10 is compressed in the minor axis direction DN.
In the intermediate portion 10S, the positive electrode plate 11, the separator 13, and the negative electrode plate 12 are stacked in the minor axis direction DN. Therefore, in the intermediate portion 10S compressed by the intermediate portion compression device PS, the positive electrode plate 11 is interposed via the separator 13. And the negative electrode plate 12 are brought close to each other. Accordingly, in the intermediate portion 10S, when a conductive foreign material generated during welding, for example, is mixed between the positive electrode plate 11 and the negative electrode plate 12, the positive electrode plate 11 and the negative electrode plate 12 are connected through the conductive foreign material. Will contact and short circuit. On the other hand, when no conductive foreign matter is mixed in the intermediate portion 10S, no short circuit occurs in the intermediate portion 10S.

Next, in the method for manufacturing the battery 1 according to the present embodiment, the intermediate portion compression stationary step (Step S4) will be described.
In this intermediate portion compression stationary step, the battery 1 is allowed to stand under a predetermined condition while the intermediate portion 10S is compressed in the minor diameter direction DN. A battery in which a short circuit due to a conductive foreign substance has occurred in the intermediate portion 10S is faster in self-discharge than the battery in which the short circuit has not occurred during this standing, and the terminal voltage V of the battery is large (for example, 100 mV). Above)
Specifically, in the intermediate compression stationary step, first, the inter-terminal voltage V is set to the first voltage V1 in the battery 1 in a state where the intermediate portion 10S is compressed in the minor diameter direction DN by the above-described intermediate compression device PS. (In this embodiment, constant current charging is performed at 1 C until it reaches 4.1 V, and then constant voltage charging is performed to adjust the state of charge (SOC) to 98%. If the voltage between the terminals does not increase even after starting constant current charging, it is considered that a short circuit between the positive and negative electrodes due to a foreign substance has already occurred, and thus charging is determined to be a short circuit.
After adjusting the SOC, the battery 1 was allowed to stand at 25 ° C. for 3 days (72 hours).

Then, the voltage measurement process (step S5) after compressing and fixing the intermediate part 10S among the manufacturing methods of the battery 1 concerning this embodiment is demonstrated. In this voltage measurement step, the value of the voltage V between the terminals of the battery 1 (second voltage V2) is measured using a known voltmeter after the intermediate compression step described above. And when the value of the measured 2nd voltage V2 has fallen 100 mV or more from the value of the 1st voltage V1 mentioned above, it is judged that the short circuit by the foreign material has arisen in the intermediate part 10S.
After the voltage measurement step in step S5 described above, the intermediate compression device PS is removed from the battery 1.

Next, in the method for manufacturing the battery 1 according to this embodiment, the end compression step (step S6) will be described. This end compression process compresses the semicylindrical end 10R of the electrode body 10 from the outside of the battery case 20 into the minor axis direction DN through the battery case 20, and also compresses the electrode body 10 in the major axis direction DM. To do.
In this end compression step, the two semi-cylindrical ends 10R, 10R are compressed in the short diameter direction DN through the battery case 20, and the battery case 20 is pressed in the long diameter direction DM, and the electrodes are passed through the battery case 20. An end compression device PU capable of compressing the body 10 in the major axis direction DM is used (see FIG. 8). The end compression device PU includes two sets of first compression portions PV1 and PV1 that can compress the semicylindrical end portion 10R with the battery case 20 (first case wall surface 23) in the short diameter direction DN, and the battery case. 20 (sealing lid 26 and case bottom 22) and a pair of second compression portions PV2 and PV2 that can be compressed by sandwiching the electrode body 10 in the major axis direction DM (see FIG. 8).

In the end compression step, two semi-cylindrical shapes are formed from the outside of the battery case 20 through the first case wall surface 23 of the battery case 20 using the pair of first compression portions PV1 and PV1 of the end compression device PU described above. The end portions 10R are respectively sandwiched in the minor axis direction DN. At this time, the surface pressure applied to the first case wall surface 23 of the battery case 20 by the first compression unit PV1 is 1.5 MPa. As a result, the two semi-cylindrical end portions 10R of the electrode body 10 are each compressed in the minor axis direction DN only at a portion adjacent to the intermediate portion 10S.
On the other hand, the battery case 20 is sandwiched from the outside in the major axis direction DM using the pair of second compression portions PV2 and PV2. At this time, the surface pressure which the 1st compression part PV1 applies to the 1st case wall surface 23 of the battery case 20 shall be 0.4 MPa. As a result, the battery case 20 is pressed inward in the long-diameter direction DM, the sealing lid 26 of the battery case 20 and the case bottom surface 22 approach each other, and the sealing lid 26 and the case bottom surface 22 are positioned at both ends of the long-diameter direction DM of the electrode body 10. The semi-cylindrical end portions 10R abut each other.
Thus, the electrode body 10 is sandwiched in the major axis direction DM by the pair of second compression portions PV2 and PV2 through the sealing lid 26 and the case bottom surface 22 of the battery case 20, so that the electrode body 10 is compressed in the major axis direction DM. Thus, the two semi-cylindrical ends 10R of the electrode body 10 are also compressed in the major axis direction DM, respectively (see FIG. 8).
Note that, due to the compression in the long diameter direction DM, the central portion of the first case wall surface 23 of the battery case 20 bulges outside the short diameter direction DN (see FIG. 8).

  As described above, in this end compression step, the two semi-cylindrical ends 10R and 10R can be compressed from the major axis direction DM and the minor axis direction DN. Therefore, in the semi-cylindrical end portion 10R, when a conductive foreign matter is mixed between the positive electrode plate 11 and the negative electrode plate 12, the positive electrode plate 11 and the negative electrode plate 12 come into contact with each other through the conductive foreign matter and short circuit occurs. Will do. On the other hand, when no conductive foreign matter is mixed in the semicylindrical end portion 10R, no short circuit occurs in the semicylindrical end portion 10R.

  Next, in the method for manufacturing the battery 1 according to the present embodiment, the end compression stationary step of Step S7 will be described. In the end compression stationary step, the battery 1 in a state where the two semi-cylindrical end portions 10R, 10R are compressed in the minor axis direction DN is left under a predetermined condition. Specifically, first, regarding the battery 1 in a state in which the semicylindrical end portion 10R is compressed in two directions (the short diameter direction DN and the long diameter direction DM) by the above-described end portion compression device PU, the above-described intermediate portion compression stationary. As in the process, constant current charging and constant voltage charging were performed to set the terminal voltage V to the first voltage V1 (corresponding to SOC 98%). Then, the battery 1 was left still for 3 days (72 hours) at the temperature of 25 degreeC similarly to the intermediate part compression stationary process.

Then, the voltage measurement process (step S8) after compressing the semicylindrical edge part 10R and leaving still among the manufacturing methods of the battery 1 concerning this embodiment is demonstrated. In this voltage measurement process, the value of the inter-terminal voltage V (third voltage V3) in the battery 1 after the end compression resting process is measured using a known voltmeter in the same manner as the voltage measurement process in step S5 described above. To do. And when the value of the measured 3rd voltage V3 has fallen 100 mV or more from the value of the 1st voltage V1 mentioned above, it is judged that the short circuit by the foreign material has arisen in the semi-cylindrical edge part 10R.
After the voltage measurement process in step S8 described above, the end compression device PU is removed from the battery 1.

Thus, in this embodiment, steps S3 to S8 of the flowchart shown in FIG. 4 were sequentially performed to inspect the battery 1 including the electrode body 10 described above. That is, the intermediate portion 10S of the electrode body 10 is compressed in the minor diameter direction DN in the intermediate portion compression step of Step S3 described above, and the intermediate portion 10S is compressed in the minor diameter direction DN in the intermediate portion compression stationary step of Step S4. The battery 1 was left still in the compressed state. Thereafter, in the voltage measurement step of step S5, the voltage V between the terminals of the battery 1 is measured, and when the second voltage V2 is lower than the first voltage V1 by 100 mV or more, a short circuit is caused in the intermediate portion 10S. Judged that it occurred.
Further, in the end compression step of step S6, the semicylindrical end portion 10R is compressed in the short diameter direction DN and the electrode body 10 is compressed in the long diameter direction DM, and in the end compression stationary step of step S7, the semicylindrical portion is compressed. The battery 1 was allowed to stand in a state where the end portion 10R was compressed in the minor axis direction DN and the electrode body 10 was compressed in the major axis direction DM. Thereafter, in the voltage measurement step of step S8, the voltage V between the terminals of the battery 1 is measured, and when the third voltage V3 is lower than the first voltage V1 by 100 mV or more, the semicylindrical end portion 10R. It was determined that a short circuit occurred in

  In this embodiment, the intermediate compression process (step S3) is the second compression process, the end compression process (step S6) is the first compression process, and the intermediate compression stationary process (step S4) is the second. In the stationary process, the end compression stationary process (step S7) is the first stationary process, the voltage measuring process in step S5 is the second voltage measuring process, and the voltage measuring process in step S8 is the first voltage measuring process. Each corresponds.

The inspection method for the battery 1 according to the present embodiment includes the end compression step S6, the end compression stationary step S7, and the voltage measurement step S8 described above. Among these, in the end compression step S6 and the end compression stationary step S7, the semicylindrical end portion 10R of the electrode body 10 is compressed in the short diameter direction DN and the electrode body 10 is compressed in the long diameter direction DM. The semi-cylindrical end portion 10R can be compressed from two directions (major axis direction DM and minor axis direction DN). Moreover, since the electrode body 10 is also compressed in the major axis direction DM through the battery case 20, the pressurization in the minor axis direction DN also suppresses deformation of the semicylindrical end portion 10R protruding outside the major axis direction DM, The semi-cylindrical end portion 10R can be sufficiently compressed in the minor axis direction DN and the major axis direction DM. For this reason, when conductive foreign matter is mixed in the semicylindrical end portion 10R, a short circuit between the positive and negative electrodes due to foreign matters in the semicylindrical end portion 10R in the end compression step S6 and the end compression stationary step S7. Can be generated. On the other hand, when no conductive foreign matter is mixed in the semicylindrical end portion 10R, a short circuit between the positive and negative electrodes does not occur in the semicylindrical end portion 10R. The battery 1 in which no conductive foreign matter is mixed can be appropriately determined.
Moreover, since the manufacturing method of the battery 1 according to this embodiment includes the end compression step S6, the end compression stationary step S7, and the voltage measurement step S8, the conductive foreign matter to the semicylindrical end portion 10R. Can produce a battery 1 free from contamination

Moreover, the inspection method of the battery 1 according to the present embodiment includes the above-described intermediate compression step S3, intermediate compression compression step S4, and voltage measurement step S5 before the above-described end compression step S6. For this reason, in addition to the semi-cylindrical end 10R in the end compression step S6 and the end compression stationary step S7, the conductive foreign matter mixed in the intermediate portion 10S in the intermediate compression step S3 and the intermediate compression stationary step S4. Thus, a short circuit between the positive and negative electrodes can be caused in the intermediate portion 10S. On the other hand, when no conductive foreign matter is mixed in the intermediate portion 10S, no short circuit occurs in the intermediate portion 10S. Therefore, the conductive foreign matter is mixed in the electrode body 10 (semi-cylindrical end portion 10R and intermediate portion 10S). It is possible to appropriately determine the battery 1 that does not have the battery.
Moreover, since the manufacturing method of the battery 1 according to this embodiment includes the above-described intermediate compression step S3, intermediate compression stationary step S4, and voltage measurement step S5 before the end compression step S6, the electrode body 10 The battery 1 can be manufactured in which no conductive foreign matter is mixed into the semicylindrical end portion 10R and the intermediate portion 10S.

By the way, when the intermediate part 10S is pressurized from the outside by the intermediate part compression device PS during the intermediate part compression step S3 (and the intermediate part compression stationary step S4), the conductive foreign matter mixed in the intermediate part 10S is removed. In some cases, the intermediate portion 10S moves to the semicylindrical end portion 10R.
On the other hand, in the inspection method of the battery 1 according to the present embodiment, the intermediate part compression step S3, the intermediate part compression stationary step S4, and the voltage measurement step S5 are performed before the end part compression step S6. Even if the conductive foreign matter moves from the intermediate portion 10S to the semi-cylindrical end portion 10R in S3 and the intermediate compression step S4, a short circuit due to the foreign matter is surely caused in the subsequent end compression step S6. Can be detected.
Moreover, in the manufacturing method of the battery 1 according to the present embodiment, the intermediate part compression step S3, the intermediate part compression stationary step S4, and the voltage measurement step S5 are performed before the end part compression step S6. Thus, it is possible to reliably manufacture the battery 1 in which no conductive foreign matter is mixed.

In the above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment and the like, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof.
For example, in the above-described embodiment, before the end portion compression step S6 (corresponding to the “first compression step”), the intermediate portion compression step S3 (corresponding to the “second compression step”), the intermediate portion compression standing step An example of the inspection method and the manufacturing method of the battery 1 including S4 (corresponding to “second standing step”) and voltage measuring step S5 (corresponding to “second voltage measuring step”) is illustrated. However, after the voltage measurement step (corresponding to the “first voltage measurement step”) in step S8, a battery inspection method or manufacturing method including the second compression step, the second stationary step, and the second voltage measurement step may be used. .
Even in this case, as in the above-described embodiment, it is possible to appropriately determine a battery in which no foreign matter is mixed in the electrode body (semi-cylindrical end portion and intermediate portion), and to the electrode body (half-cylindrical end portion and intermediate portion) A battery free from conductive foreign matter can be manufactured.

DESCRIPTION OF SYMBOLS 1 Battery 10 Electrode body 10R Semi-cylindrical edge part 10S Middle part 11 Positive electrode plate 12 Negative electrode plate 13 Separator 20 Battery case AX Winding axis DM Long diameter direction DN Short diameter direction PJ Cross section V Terminal voltage

Claims (6)

Each is a wound electrode body in which a belt-like positive electrode plate, a negative electrode plate, and a separator are wound around a winding axis, and the cross section is an oval shape;
A battery case containing the electrode body therein, and a battery inspection method comprising:
The electrode body is
A semi-cylindrical end portion that is located at both ends of the major axis direction of the oval shape, and the positive electrode plate, the separator, and the negative electrode plate are each bent into a semi-cylindrical shape;
An intermediate portion located between the semicylindrical ends, wherein the positive electrode plate, the separator and the negative electrode plate are laminated in the minor axis direction of the ellipse,
A first compression step of compressing the semicylindrical end of the electrode body in the minor axis direction and compressing the electrode body in the major axis direction from the outside of the battery case via the battery case;
A first stationary step of resting the battery in a state where the semicylindrical end portion is compressed in the minor axis direction and the electrode body is compressed in the major axis direction;
A battery inspection method comprising: a first voltage measurement step of measuring a voltage between terminals of the battery after the first stationary step. The battery inspection method according to claim 1,
A second compression step of compressing the intermediate portion of the electrode body in the minor axis direction from the outside of the battery case through the battery case before the first compression step or after the first voltage measurement step;
A second stationary step of stationary the battery in a state where the intermediate portion is compressed in the minor axis direction; and
A battery inspection method comprising: a second voltage measurement step of measuring a voltage between terminals of the battery after the second stationary step. The battery inspection method according to claim 2,
A battery inspection method in which the second compression step, the second stationary step, and the second voltage measurement step are performed before the first compression step. Each is a wound electrode body in which a belt-like positive electrode plate, a negative electrode plate, and a separator are wound around a winding axis, and the cross section is an oval shape;
A battery case containing the electrode body therein, and a battery manufacturing method comprising:
The electrode body is
A semi-cylindrical end portion that is located at both ends of the major axis direction of the oval shape, and the positive electrode plate, the separator, and the negative electrode plate are each bent into a semi-cylindrical shape;
An intermediate portion located between the semicylindrical ends, wherein the positive electrode plate, the separator and the negative electrode plate are laminated in the minor axis direction of the ellipse,
A first compression step of compressing the semicylindrical end of the electrode body in the minor axis direction and compressing the electrode body in the major axis direction from the outside of the battery case via the battery case;
A first stationary step of resting the battery in a state where the semicylindrical end portion is compressed in the minor axis direction and the electrode body is compressed in the major axis direction;
A battery manufacturing method comprising: a first voltage measuring step for measuring a voltage between terminals of the battery after the first standing step. A method of manufacturing a battery according to claim 4,
A second compression step of compressing the intermediate portion of the electrode body in the minor axis direction from the outside of the battery case through the battery case before the first compression step or after the first voltage measurement step;
A second stationary step of stationary the battery in a state where the intermediate portion is compressed in the minor axis direction; and
A battery manufacturing method comprising: a second voltage measuring step of measuring a voltage between terminals of the battery after the second stationary step. A battery manufacturing method according to claim 5,
A method for manufacturing a battery, wherein the second compression step, the second stationary step, and the second voltage measurement step are performed before the first compression step.

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