JP6659483B2 - Inspection method of joining condition between electrode tab and bus bar - Google Patents

Description

  The present invention relates to a method for inspecting a joint state between an electrode tab and a bus bar.

  For example, a plurality of assembled batteries are mounted on a vehicle such as an electric vehicle, and are used as a power source for driving a vehicle motor. The assembled battery includes a flat battery body including a power generating element and an electrode tab derived from the battery body, and electrically connects a plurality of cells stacked in the thickness direction thereof and at least electrode tabs of different cells. A bus bar.

  In the manufacture of such an assembled battery, a technique of joining an electrode tab and a bus bar by, for example, laser welding is known (see Patent Document 1).

JP 2011-210725 A

  By the way, if the quality of the bonding state between the electrode tab and the bus bar is left to the visual inspection by a worker or the bonding strength inspection performed by pressing a predetermined tool against the electrode tab, the level of the inspection greatly varies, and the inspection is performed. May be insufficient.

  SUMMARY OF THE INVENTION The present invention has been made to meet the above-mentioned demands, and an object of the present invention is to provide an inspection method capable of sufficiently inspecting a joint state between an electrode tab and a bus bar.

  In order to achieve the above object, a method for inspecting a joint state between an electrode tab and a bus bar according to the present invention includes a flat battery body including a power generation element and an electrode tab derived from the battery body, and laminated in a thickness direction thereof. A method of inspecting a joint state between the electrode tabs of the plurality of unit cells and a bus bar having holes for inserting the electrode tabs and electrically connecting the electrode tabs of at least different unit cells. This inspection method includes an inspection step of inspecting a joint state between the electrode tab and the bus bar in a state where the electrode tab and the bus bar are joined to the bus bar by inserting the tip end so as to project from the hole by bending the tip end. .

  According to the method for inspecting the joint state between the electrode tab and the bus bar, the joint state between the electrode tab and the bus bar can be sufficiently inspected.

FIG. 2 is a perspective view showing the battery pack according to the first embodiment. FIG. 2 is an exploded perspective view showing the assembled battery shown in FIG. 1 for each constituent member. It is a figure which shows the principal part of the manufacturing method of the assembled battery which concerns on 1st Embodiment, and is a perspective view which shows typically the state which inserted the electrode tab in the hole of the bus bar. FIG. 4 is a view showing a main part of the method of manufacturing the battery assembly continued from the state shown in FIG. 3, and is an end view schematically showing a state in which electrode tabs are welded to a bus bar. FIG. 5 is a diagram illustrating a main part of the method of manufacturing the battery assembly and an inspection method continued from the state illustrated in FIG. 4, wherein a change in the shape of the electrode tab is monitored by a camera while the electrode tab is bent along the bus bar by a pressing roller. FIG. 3 is an end view schematically showing a state in which the state of FIG. It is a figure which shows the principal part of the manufacturing method of the assembled battery which concerns on the modified example of 1st Embodiment, and the inspection method, while a press roller rolls several electrode tabs in order along a bus bar, and a camera is used for an electrode tab. FIG. 6 is an end view schematically showing a state in which a change in the shape of the sample is monitored. It is a figure which shows the principal part of the manufacturing method of the assembled battery which concerns on 2nd Embodiment, and the inspection method, bending the electrode tab along a bus bar with a press roller, and monitoring the change of the pressure applied to a press roller with a sensor. It is an end elevation which shows the state which is typically.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same members will be denoted by the same reference characters, without redundant description. In the drawings, the size and ratio of each member may be exaggerated for easy understanding of the embodiment, and may be different from the actual size or ratio.

  In the figure, the directions of the battery pack 100 are indicated by arrows represented by X, Y, and Z. The direction of the arrow represented by X indicates the longitudinal direction X of the battery pack 100. The direction of the arrow represented by Y indicates the short direction Y of the battery pack 100. The direction of the arrow represented by Z indicates the stacking direction Z of the battery pack 100.

(1st Embodiment)
FIG. 1 is a perspective view showing the battery pack 100 according to the first embodiment. FIG. 2 is an exploded perspective view showing the assembled battery 100 shown in FIG. 1 for each constituent member.

  FIG. 3 is a diagram illustrating a main part of the method of manufacturing the battery pack 100 according to the first embodiment, and is a perspective view schematically illustrating a state where the electrode tab 112 is inserted into the hole 132d of the bus bar 132. . FIG. 4 is a view showing the main part of the method of manufacturing battery pack 100 continuing from the state shown in FIG. 3, and is an end view schematically showing a state where electrode tab 112 is welded to bus bar 132. FIG. 5 is a diagram illustrating a main part of the method of manufacturing the assembled battery 100 and an inspection method continued from the state illustrated in FIG. 4, wherein the electrode tab 112 is bent along the bus bar 132 by the pressing roller 211 while the camera 213 It is an end elevation which shows the state which monitors the change of the shape of the electrode tab 112 typically.

  First, with reference to FIGS. 3 to 5 in addition to FIGS. 1 and 2, a description will be given of an assembled battery 100 manufactured while inspecting a bonding state between the electrode tab 112 and the bus bar 132.

  A plurality of battery packs 100 are mounted on a vehicle such as an electric vehicle, and are used as a power supply for driving a vehicle motor. The assembled battery 100 includes a plurality of cells 110, a housing unit 120 that integrally holds the plurality of cells 110, and a bus bar unit 130 that electrically connects the plurality of cells 110.

  The configuration of the cell 110 will be described in detail.

  The cell 110 corresponds to, for example, a lithium ion secondary battery. A plurality of cells 110 are connected in series to satisfy the specification of the driving voltage of the vehicle motor. A plurality of cells 110 are connected in parallel in order to extend the traveling distance of the vehicle. The unit cell 110 is configured by, for example, connecting three unit cells 110 connected in parallel in seven stages in series. Since a plurality of assembled batteries 100 are mounted on the vehicle, the unit cells 110 electrically connected in three parallel and seven series in one assembled battery 100 are further electrically connected in series and used.

  As shown in FIG. 2, the unit cell 110 includes a first cell subassembly 110M including three unit cells 110 electrically connected in parallel and another three unit cell electrically connected in parallel in one assembled battery 100. The second cell subassembly 110N composed of 110 is connected in series. The first cell subassembly 110M corresponds to three single cells 110 located at the first (lowest), third, fifth, and seventh (top) stages in one battery pack 100. The second cell sub-assembly 110N corresponds to three single cells 110 located at the second, fourth, and sixth tiers in one battery pack 100.

  The first cell subassembly 110M and the second cell subassembly 110N have the same configuration. However, the second cell subassembly 110N reverses the top and bottom of the cell 110 included in the first cell subassembly 110M. The first cell sub-assemblies 110M and the second cell sub-assemblies 110N are alternately stacked. Therefore, as shown in FIGS. 2 to 4, three anode-side electrode tabs 112 </ b> A and three cathode-side electrode tabs 112 </ b> K are alternately located along the stacking direction Z.

  As shown in FIG. 4, the unit cell 110 includes a power generation element 111 that performs charging and discharging, an electrode tab 112 joined to the power generation element 111, and a laminate film 113 that seals the power generation element 111. As shown in FIG. 4, the power generation element 111 and the pair of laminate films 113 constitute a flat battery main body 110h.

  The power generation element 111 supplies electric power from an outdoor charging station or the like, and then supplies the electric power to the vehicle motor or the like by discharging the electric power. The power generation element 111 is configured by stacking a plurality of pairs of anodes and cathodes separated by a separator.

  As shown in FIG. 2, the electrode tab 112 includes an anode-side electrode tab 112A and a cathode-side electrode tab 112K. The base end of the anode-side electrode tab 112A is joined to all anodes included in the power generation element 111. The anode-side electrode tab 112A is formed in a thin plate shape, and is made of aluminum according to the characteristics of the anode. The base end of the cathode-side electrode tab 112K is joined to all the cathodes included in the power generation element 111. The cathode-side electrode tab 112K is formed of a thin plate, and is made of copper according to the characteristics of the cathode. The distal end 112s of the electrode tab 112 is welded at a portion such as a hole 132d of the bus bar 132 as shown in FIG. 4 to form a joint 112t, and as shown in FIG. 132 is bent upward along the side surface 132a.

  The laminate film 113 is formed of a pair, and seals the power generating element 111 from above and below along the laminating direction Z, as shown in FIGS. As shown in FIGS. 2 and 4, the pair of laminate films 113 are formed by leading the anode-side electrode tab 112A and the cathode-side electrode tab 112K outward from the gap between the one end portions 113a along the short direction Y. I have. The laminate film 113 includes a metal foil and an insulating sheet that covers the metal foil from above and below.

  The configuration of the housing unit 120 will be described in detail.

  As shown in FIGS. 1 to 3, the pair of first spacers 121 and second spacers 122 support the unit cell 110 from front and rear along the longitudinal direction X. The pair of first spacers 121 and the second spacers 122 arrange the supporting unit cells 110 at regular intervals along the stacking direction Z. As shown in FIG. 2, the first spacer 121 supports the unit cell 110 on the side provided with the electrode tab 112. The second spacer 122 supports the unit cell 110 on the side without the electrode tab 112 so as to face the first spacer 121 in the longitudinal direction X of the unit cell 110. The second spacer 122 has the same configuration as the first spacer 121.

  As shown in FIG. 2, the first spacer 121 is formed in a long plate shape having irregularities, and is made of reinforced plastics having an insulating property. As shown in FIG. 2, the first spacer 121 is provided so as to face one end 113a of the pair of laminate films 113. As shown in FIGS. 2 and 4, the first spacer 121 supports one end 113a of the laminate film 113 by a flat support surface 121b. The first spacer 121 includes a pair of cylindrical connection pins 121c protruding upward at both ends of the support surface 121b. The pair of connection pins 121c position the cell 110 by inserting connection holes 113c opened at four corners of the laminate film 113 shown in FIG.

  As shown in FIG. 4, the plurality of first spacers 121 are in contact with an upper surface 121 a of one first spacer 121 and a lower surface 121 d of another first spacer 121. The first spacer 121 is formed by fitting a positioning pin 121 e having a cylindrical shape protruding from an upper surface 121 a of one first spacer 121 with a positioning hole 121 f opened in a lower surface 121 d of the other first spacer 121. Positioned relative to each other. As shown in FIG. 2, the first spacer 121 has, at both ends, locate holes 121 g for inserting bolts for connecting the plurality of assembled batteries 100 while positioning them along the stacking direction Z.

  The second spacer 122 has the same configuration as the first spacer 121. The second spacer 122 includes a support surface 122b that supports the other end 113b of the laminated film 113, a connection pin that positions the unit cell 110, and a bolt that positions and connects the plurality of assembled batteries 100 along the stacking direction Z. And a locating hole for inserting the same.

  As shown in FIGS. 1 and 2, the upper pressure plate 123 and the lower pressure plate 124 press the power generation element 111 of each cell 110 while holding the plurality of cells 110 from above and below. . The upper pressing plate 123 is formed in a plate shape having irregularities, and is made of metal having sufficient rigidity. The upper pressing plate 123 is provided on a horizontal plane. As shown in FIG. 2, the upper pressing plate 123 has a pressing surface 123a that presses the power generating element 111 downward. The pressing surface 123 a is formed flat, and protrudes downward from the central portion of the upper pressing plate 123. The upper pressure plate 123 has a locate hole 123b into which a bolt connecting the assembled batteries 100 is inserted. The locate holes 123b are formed of through holes and open at four corners of the upper pressure plate 123.

  As shown in FIG. 2, the lower pressing plate 124 has the same shape as the upper pressing plate 123, and is provided so that the top and bottom of the upper pressing plate 123 are reversed. Like the upper pressing plate 123, the lower pressing plate 124 includes a pressing surface 124a for pressing the power generating element 111 upward and a locate hole 124b for inserting a bolt connecting the assembled batteries 100 to each other.

  As shown in FIGS. 1 and 2, the pair of side plates 125 are fixed to the upper pressing plate 123 and the lower pressing plate 124 in a state where the power generating element 111 of each unit cell 110 is pressurized. That is, the pair of side plates 125 keep the distance between the upper pressing plate 123 and the lower pressing plate 124 constant. In addition, the pair of side plates 125 cover and protect the side surfaces of the stacked unit cells 110 along the longitudinal direction X. The side plate 125 is formed in a flat plate shape and is made of metal. The pair of side plates 125 are provided upright so as to face both side surfaces of the stacked unit cells 110 along the longitudinal direction X. The pair of side plates 125 are welded to the upper pressing plate 123 and the lower pressing plate 124.

  The configuration of the bus bar unit 130 will be described in detail.

  As shown in FIG. 2, the bus bar holder 131 integrally holds six bus bars 132, one anode-side terminal bus bar 133, and one cathode-side terminal 136. As shown in FIGS. 2 and 3, the bus bar holder 131 is formed from a frame body in which a columnar central portion 131a provided at the center and a pair of columnar end portions 131b separated from both ends from the central portion 131a are formed. , Made of an insulating resin. The bus bar holder 131 is provided upright so as to face the electrode tabs 112 of the plurality of unit cells 110 that are stacked. The bus bar holder 131 has a pair of end portions 131b fitted to both ends of the stacked first spacers 121.

  The bus bar 132 electrically connects the electrode tabs 112 of the different cells 110 as shown in FIGS. 2 to 5. As shown in FIG. 3, the bus bar 132 is formed by bending one end 132b and the other end 132c of a flat side surface 132a, respectively, and is made of conductive copper or aluminum. The bus bar 132 is provided upright so as to face the bus bar holder 131 with the one end 132b and the other end 132c positioned on the left and right. As shown in FIG. 3, the bus bar 132 is provided with five holes 132d for inserting the electrode tabs 112 on the side surface 132a at regular intervals vertically. Each of the holes 132d has a rectangular opening elongated in the horizontal direction according to the shape of the electrode tab 112 formed of a thin plate. The bus bar 132 has one end 132b and the other end 132c fitted and fixed between the central portion 131a and the end portion 131b of the bus bar holder 131 with the electrode tab 112 inserted into the hole 132d.

  The bus bar 132 joins the electrode tabs 112 of the unit cells 110 arranged vertically as shown in FIGS. 2 and 3. Here, the assembled battery 100 includes three electric cells 110 (first cell subassembly 110M) electrically connected in parallel and another three electric cells 110 (second cell subassembly 110N) electrically connected in parallel. Connected and configured. Therefore, the bus bar 132 includes three vertically arranged anode-side electrode tabs 112A in the first cell sub-assembly 110M and three vertically arranged cathodes in the second cell sub-assembly 110N disposed immediately below (or immediately above) the first cell sub-assembly 110M. The side electrode tab 112K is joined.

  As shown in FIGS. 3 and 4, the bus bar 132 inserts five electrode tabs 112 out of the six electrode tabs 112 to be joined into the corresponding holes 132d, and inserts one electrode tab 112 (for example, (The cathode side electrode tab 112K) is brought into contact with the lower end 132e. The six electrode tabs 112 joined to the bus bar 132 are bent upward so as to abut along the side surface 132a as shown in FIG. 5 in a state of being welded to the side surface 132a of the bus bar 132 as shown in FIG. I have.

  As shown in FIG. 2, the anode-side terminal bus bar 133 is a bus bar located at the upper right of the figure among eight bus bars arranged in a matrix. The anode-side termination bus bar 133 joins only the anode-side electrode tabs 112A of the top three unit cells 110 among the 21 unit cells 110 arranged vertically (three parallels and seven series). The anode-side terminal bus bar 133 has a configuration in which the lower half of the bus bar 132 is deleted. The anode-side terminal bus bar 133 has two upper and lower holes 133d.

  The anode-side termination bus bar 133 is joined in a state where two anode-side electrode tabs 112A among the three anode-side electrode tabs 112A to be joined are inserted into the holes 133d, and one anode-side electrode tab 112A (located at the bottom). (The electrode tab to be used) is in contact with the lower end 133e. The three anode-side electrode tabs 112A are bent upward so as to abut along the side surface of the anode-side terminal bus bar 133.

  As shown in FIG. 2, the cathode-side terminal bus bar 134 is a bus bar located at the lower left of the figure among eight bus bars arranged in a matrix. The cathode-side termination bus bar 134 joins only the cathode-side electrode tabs 112K of the bottom three unit cells 110 among the 21 unit cells 110 arranged vertically (three parallels and seven series). The cathode-side terminal bus bar 134 has the same shape as the anode-side terminal bus bar 133.

  The cathode-side termination bus bar 134 is joined in a state where two cathode-side electrode tabs 112K of the three cathode-side electrode tabs 112K to be joined are inserted into the holes 134d, and one cathode-side electrode tab 112K (located at the bottom). Electrode tabs) are in contact with the lower end 134e. The three cathode-side electrode tabs 112K are bent upward so as to abut along the side surface of the cathode-side terminal bus bar 134.

  As shown in FIGS. 1 and 2, the anode-side terminal 135 has the anode-side terminals of the plurality of electrically connected single cells 110 facing external input / output terminals. As shown in FIG. 2, the anode-side terminal 135 is joined to an anode-side terminal bus bar 133 located at the upper right in the figure among bus bars arranged in a matrix. The anode-side terminal 135 is formed in a plate shape with both ends bent, and is made of a conductive metal.

  As shown in FIGS. 1 and 2, the cathode terminal 136 has the cathode-side terminals of the plurality of electrically connected cells 110 facing external input / output terminals. As shown in FIG. 2, the cathode terminal 136 is joined to the cathode terminal bus bar 134 located at the lower left in the figure among the eight bus bars arranged in a matrix. The cathode terminal 136 has the same shape as the anode terminal 135.

  The protection cover 137 protects the bus bar 132 and the like as shown in FIGS. That is, the protective cover 137 integrally covers the six bus bars 132, one anode-side terminal bus bar 133, and one cathode-side terminal 136, so that each bus bar comes into contact with another member or the like and is electrically connected. Prevent short circuit from occurring. As shown in FIG. 2, the protective cover 137 is formed so that one end 137b and the other end 137c located at both ends of the flat side surface 137a are bent 90 degrees in the same direction like nails. It is made of insulating plastics.

  The protective cover 137 has one end 137b and the other end 137c positioned vertically, and is provided upright so that the ends of the one end 137b and the other end 137c face the bus bar holder 131. The protective cover 137 covers and fixes each bus bar 132 with the side surface 137a, and sandwiches and fixes the bus bar holder 131 from above and below with one end 137b and the other end 137c. The protective cover 137 includes a first opening 137d made of a rectangular hole and facing the anode terminal 135 to the outside, and a second opening 137e made of a rectangular hole and facing the cathode terminal 136 to the outside. In preparation.

  Next, with reference to FIGS. 3 to 5, a description will be given of a main part of a method of manufacturing the battery pack 100 and a method of inspecting a bonding state between the electrode tab 112 and the bus bar 132.

  FIG. 3 shows a main part (assembly of the bus bar 132 and the electrode tab 112) of the method of manufacturing the battery pack 100.

  As shown in FIG. 3, among the five holes 132 d vertically opened in the bus bar 132, among the six electrode tabs 112 arranged vertically (three cathode-side electrode tabs 112 </ b> K and three anode-side electrode tabs 112 </ b> A). The upper five electrode tabs 112 are inserted. Further, one electrode tab 112 (the lowermost anode tab 112A) is brought into contact with the lower end 132e of the bus bar 132.

  FIG. 4 shows a main part of the method of manufacturing the battery pack 100 (welding of the electrode tab 112 to the bus bar 132).

  As shown in FIG. 4, the laser beam L is emitted from the laser oscillator 201 to five holes 132d and one lower end 132e of the bus bar 132 into which the tip 112s of the electrode tab 112 is inserted. Each tip 112s is welded at the position of the hole 132d or the lower end 132e of the bus bar 132 to form a joint 112t. The joint 112t is formed in the horizontal direction (short direction Y) along the hole 132d or the lower end 132e. That is, the joint portion 112t is formed linearly by, for example, seam welding.

  The laser oscillator 201 is composed of, for example, a YAG (yttrium aluminum garnet) laser. The laser oscillator 201 is capable of scanning the laser beam L in the horizontal direction (transverse direction Y), and is moved in the vertical direction (stacking direction Z) by a translation stage (not shown) that moves in the stacking direction Z. . The laser oscillator 201 may be configured so that its position is fixed and the laser beam L is scanned in a horizontal direction and a vertical direction by a galvanomirror.

  FIG. 5 shows a main part of the method of manufacturing the battery pack 100 (bending of the electrode tab 112) and an inspection method (a method of inspecting a joint state between the electrode tab 112 and the bus bar 132).

  Here, the inspection method includes a flat battery body 110h including a power generation element 111 and an electrode tab 112 derived from the battery body 110h, and includes an electrode tab 112 of a plurality of unit cells 110 stacked in the thickness direction, This is a method of inspecting a joint state between a bus bar (for example, 132) having holes (for example, holes 132d) into which the tabs 112 are inserted and electrically connecting at least the electrode tabs 112 of different cells 110. That is, in the inspection step, the joint state between the electrode tab 112 and the bus bar 132 in a state where the tip section 112 s is inserted into the hole 132 d so as to project from the hole 132 d and joined to the bus bar 132 is inspected by bending the tip section 112 s. Further, in the inspection step, the distal end portion 112s protruding from the lower end 132e of the bus bar 132 and joined is further bent for inspection.

  Specifically, as shown in FIG. 5, while the electrode tab 112 is bent so as to be in contact with the bus bar 132 by the pressing roller 211, a change in the shape of the electrode tab 112 is constantly monitored by the camera 213. The bending of the electrode tab 112 in the manufacture of the assembled battery 100 also serves as the bending of the electrode tab 112 in the inspection of the joint state between the electrode tab 112 and the bus bar 132. In the inspection step, the pressing roller 211 is used to press and bend the distal end portion 112s from the side where the joint portion 112t is formed (lower in FIG. 5) to the opposite side (upper in FIG. 5) to bend the distal end portion 112s. The portion 112s is brought into contact with the side surface 132a of the bus bar 132.

  As shown in FIG. 5, the pressing roller 211 has a cylindrical shape extending in the horizontal direction (short direction Y), and is made of, for example, hard resin or metal. Using the pressing roller 211, the distal end portion 112s of the electrode tab 112 is bent while being pressed. The pressing rollers 211 are located at regular intervals along the stacking direction Z so as to correspond to the plurality of electrode tabs 112. The pressing roller 211 may be configured to be rotatable or may be configured not to rotate.

  The support member 212 is, as shown in FIG. The support member 212 rotatably supports the pressing roller 211 on the distal end side. The base end of the support member 212 is joined to a biaxial translation stage (not shown) that moves along the stacking direction Z and the longitudinal direction X. The support member 212 is moved toward the electrode tab 112 along the longitudinal direction X (the pressing roller 211 approaches the electrode tab 112) using the linear motion stage, and then moved upward (pressed) along the stacking direction Z. The electrode tab 112 is bent upward by the roller 211), and then returns to the initial position.

  The camera 213 includes, for example, a CCD camera as shown in FIG. Using the camera 213, a change in the shape of the tip 112s bent by the pressing roller 211 is observed. The observation of the distal end portion 112s by the camera 213 may be during the bending of the distal end portion 112s by the pressing roller 211, or may be performed after the bending of the distal end portion 112s by the pressing roller 211 is completed.

  The controller 221 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU executes a control program relating to a two-axis linear movement stage for moving the support member 212, the camera 213, and the like. The ROM stores a control program. The RAM temporarily stores a result of an operation generated by executing the control program.

  The operation and effect of the first embodiment described above will be described.

  A method for inspecting the joint state between the electrode tab 112 and the bus bar 132 is a method of inspecting a plurality of single cells including a flat battery body 110h including the power generation element 111 and an electrode tab 112 derived from the battery body 110h and stacked in the thickness direction. The joint state between the electrode tab 112 in 110 and a bus bar (for example, 132) having a hole (for example, hole 132d) for inserting the electrode tab 112 and electrically connecting at least the electrode tabs 112 of different cells 110 is inspected. Is the way. This inspection method includes an inspection step of bending the distal end portion 112s to inspect the joined state between the electrode tab 112 and the bus bar 132 in a state where the distal end portion 112s is inserted into the hole 132d so as to protrude from the hole 132d and joined to the bus bar 132. Have.

  According to this inspection method, the joint state between the electrode tab 112 and the bus bar 132 is inspected by bending the distal end portion 112 s of the electrode tab 112 inserted into and joined to the hole 132 d of the bus bar 132. According to this inspection, the electrode tab 112 having a sufficient joint state with the bus bar 132 is bent while being joined to the bus bar 132, and the electrode tab 112 having an insufficient joint state with the bus bar 132 is peeled off from the bus bar 132. Bendable. Therefore, according to this inspection method, the bonding state between the electrode tab 112 and the bus bar 132 can be sufficiently inspected.

  In particular, according to this inspection method, the joint state between the electrode tab 112 and the bus bar 132 can be inspected very easily at all and all locations. And the connection state between the bus bar 132 and the bus bar 132 can be inspected. In the first place, according to this inspection method, the joining portion 112t between the electrode tab 112 and the bus bar 132 can be confirmed from the outside, so that the joining state between the electrode tab 112 and the bus bar 132 is very easy to confirm.

  In the inspection step, it is preferable to further bend the distal end portion 112s protruding from the outer peripheral edge (for example, the lower end 132e) of the bus bar (for example, the bus bar 132).

  According to such an inspection method, the joint state between the electrode tab 112 and the bus bar 132 is inspected by bending the distal end 112 s of the electrode tab 112 which is projected and joined from the lower end 132 e of the bus bar 132. According to this inspection, the electrode tab 112 having a sufficient bonding state with the bus bar 132 is bent while being bonded to the bus bar 132, and the electrode tab 112 having a poor bonding state with the bus bar 132 is separated from the bus bar 132. Therefore, according to this inspection method, the bonding state between the electrode tab 112 and the bus bar 132 can be sufficiently inspected.

  In the inspection step, it is preferable to bend the front end portion 112s so as to contact the bus bar 132.

  According to such an inspection method, the angle at which the tip portion 112s of the electrode tab 112 is bent can be defined by the side surface 132a of the bus bar 132. That is, each tip 112s can be bent evenly. Therefore, according to this inspection method, the joint state between the electrode tab 112 and the bus bar 132 can be quantitatively inspected at a fixed bending angle.

  In the inspection step, it is preferable to bend the front end portion 112s, which is joined at the position of the bus bar 132 and the hole 132d to form the joint portion 112t, from the side where the joint portion 112t is formed to the opposite side.

  According to such an inspection method, the distal end portion 112s is bent toward the bus bar 132 to be sufficiently contacted without being affected by the shape (convex, concave, or uneven shape) of the joint portion 112t of the electrode tab 112. Can be. Therefore, according to this inspection method, the bonding state between the electrode tab 112 and the bus bar 132 can be stably inspected regardless of the shape of the bonding portion 112t.

  In the inspection step, it is preferable to use the pressing roller 211 that presses and bends the distal end portion 112s, and inspects the joining state based on a change in the shape of the distal end portion 112s that is bent by the pressing roller 211.

  According to such an inspection method, the joint state between the electrode tab 112 and the bus bar 132 can be quantitatively inspected based on a change in the shape of the tip 112s of the electrode tab 112 pressed by the pressing roller 211. The change in the shape of the distal end portion 112s is recognized by image analysis of the distal end portion 112s using the camera 213, optical path analysis of the reflected light of the laser beam applied to the distal end portion 112s, or visual observation of the distal end portion 112s by an operator. .

  In the inspection step, it is preferable to observe the change in the shape of the distal end portion 112s while bending the distal end portion 112s by the pressing roller 211.

  According to such an inspection method, when the connection state between the electrode tab 112 and the bus bar 132 is defective, the state can be immediately detected. Therefore, according to this inspection method, it is possible to minimize the occurrence of a product having a defective connection, and to quickly analyze the cause of the defective connection.

  In this inspection method, it is preferable to use the bus bar 132 having the hole 132d that is opened larger than the thickness of the tip 112s.

  According to such an inspection method, it is possible to inspect by bending the distal end portion 112s of the electrode tab 112 sufficiently inserted into the hole 132d of the bus bar 132. That is, according to this inspection method, the inspection can be performed by bending the distal end portion 112s sufficiently protruding from the hole 132d without being affected by a stacking error or the like of the unit cells 110.

(Modification 1 of the first embodiment)
FIG. 6 is a diagram illustrating a main part of a method of manufacturing the assembled battery 100 and a test method according to a modification of the first embodiment. FIG. 4 is an end view schematically showing a state in which the sheet is bent to the right.

  The manufacturing method and the inspection method of the battery pack 100 according to the first modification of the first embodiment are different from the first embodiment described above in that a plurality of vertically arranged electrode tabs 112 are sequentially bent by one pressing roller 211. The manufacturing method and the inspection method of the battery pack 100 are different.

  In a first modification of the first embodiment, a configuration different from the first embodiment will be described.

  In the inspection process according to the first modification of the first embodiment, as shown in FIG. 6, one pressing roller 211 pushes the tip 112s of each of the electrode tabs 112 provided on the stacked unit cells 110 from below. Press and bend in order. The camera 213 constantly monitors a change in the shape of the distal end portion 112s that is successively bent by one pressing roller 211.

  The operation and effect of the first modification of the first embodiment described above will be described.

  In the inspection process, the plurality of tip portions 112s are sequentially pressed by the pressing roller 211 and bent.

  According to such an inspection method, the joint state between each electrode tab 112 and the bus bar 132 can be inspected in the same state by bending the tip 112s of each electrode tab 112 by the same pressing roller 211. . Therefore, according to this inspection method, the bonding state between each of the electrode tabs 112 and the bus bar 132 can be inspected uniformly without variation.

  According to such an inspection method, since a plurality of pressing rollers 211 are not required, it is easy to prevent interference between the pressing rollers 211 and surrounding members (components of the inspection device and components of the battery pack 100). In addition, the cost of the inspection device can be reduced.

(2nd Embodiment)
FIG. 7 is a diagram illustrating a main part of a method of manufacturing the battery pack 100 according to the second embodiment and an inspection method. While the electrode tab 112 is bent along the bus bar 132 by the pressing roller 211, the pressing roller is It is an end elevation which shows the state which monitors the change of the pressure applied to 211 typically.

  The manufacturing method and the inspection method of the battery pack 100 according to the second embodiment are described above in that the bonding state between the electrode tab 112 and the bus bar 132 is inspected by monitoring a change in pressure applied to the pressing roller 211. This is different from the manufacturing method and the inspection method of the battery pack 100 according to the embodiment and the modified example thereof.

  In the second embodiment, a configuration different from the above-described first embodiment and its modification will be described.

  In the inspection process of the second embodiment, as shown in FIG. 7, a sensor 214 is provided at a base end portion of a support member 212 that rotatably supports the pressing roller 211. The sensor 214 is a so-called pressure sensor, and detects a stress applied to the pressing roller 211 from the tip 112 s of the electrode tab 112. The sensor 214 transmits the detected fluctuation of the pressure to the controller 221. The controller 221 emits a warning sound by a speaker (not shown) when the pressure value received from the sensor 214 deviates from a predetermined pressure fluctuation (for example, a sudden drop in pressure), or the pressure value received from the sensor 214. Is displayed as a waveform on a display device (not shown).

  The pressing roller 211 receives a stronger repulsive force from the distal end portion 112s as the pressing roller 211 is pressed strongly against the bent distal end portion 112s. Therefore, the sensor 214 detects a relatively high pressure in proportion to the pressing force with which the pressing roller 211 presses the tip 112s. It is necessary that the pressing roller 211 presses and bends the tip 112s more strongly as the total length of the tip 112s to be bent is longer. Therefore, the sensor 214 detects a relatively high pressure in proportion to the length of the leading end 112s that the pressing roller 211 bends.

  When the tip 112s pressed by the pressing roller 211 does not peel off from the bus bar 132, the pressure detected by the sensor 214 increases until immediately before the tip 112s contacts the side surface 132a of the bus bar 132. On the other hand, when the tip 112s pressed by the pressing roller 211 is separated from the bus bar 132, the pressure detected by the sensor 214 suddenly shifts such that the tip 112s is retracted by the pressing of the pressing roller 211. Decrease.

  The operation and effect of the second embodiment described above will be described.

  In the inspection process, the joining state is inspected based on a change in stress applied to the pressing roller 211 from the distal end 112s by using the pressing roller 211 that presses and bends the front end 112s.

  According to such an inspection method, if the electrode tab 112 and the bus bar 132 are sufficiently bonded, the electrode tab 112 does not peel off from the bus bar 132. The applied stress increases to a certain value. On the other hand, if the joining state between the electrode tab 112 and the bus bar 132 is insufficient, the electrode tab 112 is peeled off from the bus bar 132, and the leading end 112s is displaced by the pushing of the leading end 112s by the pressing roller 211, and the pushing is performed. The stress applied to the roller 211 decreases halfway. Therefore, according to this inspection method, the bonding state between the electrode tab 112 and the bus bar 132 can be sufficiently inspected with a very simple configuration.

  In the inspection step, it is preferable that the change in stress is defined by the pressing force of the pressing roller 211 against the tip 112s and the length of the tip 112s to be bent.

  According to such an inspection method, a prescribed torque arbitrarily set can be applied to the distal end portion 112s of the electrode tab 112 with a very simple configuration. Therefore, the joining state between the electrode tab 112 and the bus bar 132 can be quantitatively inspected by the prescribed bending force.

  In addition, the present invention can be variously modified based on the configurations described in the claims, and those modifications are also included in the scope of the present invention.

  For example, while the conduction state between the electrode tab 112 and the bus bar 132 and the like is monitored by a galvanometer, the joint state between the electrode tab 112 and the bus bar 132 is inspected by bending the distal end 112 s of the bus bar 132 by the pressing roller 211. It may be configured. If the conduction state between the electrode tab 112 and the bus bar 132 or the like is temporarily interrupted or interrupted while the distal end portion 112s is bent by the pressing roller 211, the joining state between the electrode tab 112 and the bus bar 132 is poor. You can see that there is.

  Further, in the modification of the first embodiment, the number of the pressing rollers 211 is not limited to one. For example, a configuration in which a plurality of pressing rollers 211 are arranged at a sufficient distance along the stacking direction Z and a plurality of (for example, 6 or 12) tip portions 112s are sequentially pressed and bent by each pressing roller 211, respectively. It may be.

100 assembled batteries,
110 cells,
110h battery body,
110M first cell subassembly,
110N second cell subassembly,
111 power generation elements,
112 electrode tabs,
112A anode side electrode tab,
112K cathode side electrode tab,
112s tip,
112t joint,
113 laminated film,
120 housing units,
121 first spacer,
122 second spacer,
123 upper pressure plate,
124 lower pressure plate,
125 side plates,
130 busbar unit,
131 bus bar holder,
132 Busba,
132a side view,
132b one end,
132c the other end,
132d hole,
132e lower end,
133 anode-side terminal busbar,
134 cathode-side termination busbar,
135 anode side terminal,
136 Cathode side terminal,
137 protective cover,
201 laser oscillator,
211 pressing roller,
212 supports,
213 camera,
214 sensors,
221 controller,
X longitudinal direction of the cell 110,
Short direction of Y cell 110,
Z The stacking direction of the cell 110.

Claims (10)

A plurality of unit cells, each having a flat battery body including a power generation element and an electrode tab derived from the battery body, and a plurality of unit cells stacked in the thickness direction thereof, and a hole for inserting the electrode tab. A method for inspecting a joint state between a bus bar that electrically connects the electrode tabs of the unit cell to each other,
An electrode tab and a bus bar, wherein the electrode tab and the bus bar have an inspection step of bending the distal end and inspecting a joint state between the electrode tab and the bus bar in a state where the electrode tab is inserted so as to project from the hole and joined to the bus bar. Inspection method of the bonding state with the   2. The method according to claim 1, wherein, in the inspection step, the distal end portion protruding from an outer peripheral edge of the bus bar and being joined is further bent. 3.   3. The method according to claim 1, wherein in the inspection step, the distal end is bent so as to contact the bus bar. 4.   4. The electrode according to claim 3, wherein, in the inspection step, the distal end portion having a joint formed by joining at a position of the bus bar and the hole is bent from a side where the joint is formed to an opposite side. Inspection method of joining condition between tab and bus bar.   5. The inspection step according to claim 1, wherein the joining state is inspected based on a change in the shape of the distal end portion bent by the pressing member, using a pressing member that presses and bends the distal end portion. Inspection method of the joining state between the electrode tab and the bus bar described in the above.   The inspection method according to claim 5, wherein in the inspection step, a change in the shape of the distal end portion is observed while the distal end portion is bent by the pressing member.   7. The method according to claim 1, wherein, in the inspection step, a joining state is inspected based on a change in stress applied to the pressing member from the distal end using a pressing member that presses and bends the distal end. Inspection method of the joining state between the electrode tab and the bus bar described in the above.   The inspection method according to claim 7, wherein in the inspection step, a change in stress is defined by a pressing force of the pressing member against the distal end portion and a length of the bent distal end portion.   The inspection method according to any one of claims 5 to 8, wherein in the inspection step, the plurality of tip portions are sequentially pressed and bent by the pressing member.   The method for inspecting a joint state between an electrode tab and a bus bar according to any one of claims 1 to 9, wherein the bus bar provided with the hole that is larger than the thickness of the tip portion is used.