JP6690920B2 - Battery pack, bus bar cover for battery pack, and method of manufacturing battery pack - Google Patents

Description

  The present invention relates to an assembled battery in which a plurality of unit cells are stacked, a bus bar cover for the assembled battery, and a method for manufacturing the assembled battery.

  Conventionally, there is an assembled battery in which a plurality of unit cells are stacked. The unit cell includes an electrode tab that inputs and outputs electric power. The electrode tabs of each unit cell are electrically connected by a bus bar having conductivity.

  In the assembled battery, there is a demand to attach the voltage detecting element to the bus bar. As a method of attaching the voltage detection element to the bus bar, a method of joining the voltage detection element to the bus bar is known (for example, see Patent Document 1).

Special table 2012-515418 gazette

  However, in the method according to Patent Document 1, when the voltage detecting element is joined to the bus bar, it is necessary to fix the voltage detecting element at a predetermined position of the bus bar using a jig. Therefore, there is a problem that the work of attaching the voltage detection element to the bus bar becomes complicated.

  Therefore, an object of the present invention is to provide an assembled battery, a bus bar cover for the assembled battery, and a method of manufacturing the assembled battery, which can efficiently attach the voltage detecting element to the bus bar.

According to one aspect of the present invention for achieving the above object, a plurality of unit cells each having a flat battery body including a power generation element and an electrode tab led out from the battery body are stacked in a thickness direction. Thus, there is provided an assembled battery having a battery group in which the tip end portion of the electrode tab is bent along the stacking direction of the unit cells. The assembled battery has terminal portions for voltage detection, is arranged so as to face the tip portions of the electrode tabs of different cells, and is attached to the battery group and a flat plate-shaped bus bar that electrically connects the tip portions. And a bus bar cover formed of an insulating material that covers the bus bar. The bus bar cover is joined to the terminal portion for voltage detection, and the voltage detection element for detecting the voltage of the unit cell and the voltage detection element in the state where it is attached to the battery group are arranged in the terminal portion for voltage detection. A holding portion that holds the voltage detecting element at a certain position, and an opening that is formed so as to penetrate in the thickness direction of the bus bar cover and that faces the joint between the voltage detecting element and the voltage detecting terminal portion. The holding part is provided with a pressurizing part for pressing the voltage detecting element against the voltage detecting terminal part of the bus bar, and the bus bar cover is such that the pressing part presses the voltage detecting element against the voltage detecting terminal part of the bus bar. It is attached to the battery group.

Further, according to another aspect of the present invention for achieving the above object, a flat plate shape is attached to a battery group formed by stacking a plurality of unit cells to electrically connect electrode tabs of different unit cells. There is provided a bus bar cover for the assembled battery, which is formed of an insulating material and covers the bus bar. The bus bar cover is joined to the voltage detecting terminal part of the bus bar, and the voltage detecting element that detects the voltage of the unit cell and the voltage detecting element when the battery is attached to the battery group are connected to the voltage detecting terminal part. A holding portion that holds the voltage detection element at a position arranged in, and an opening that is formed so as to penetrate in the thickness direction of the bus bar cover and that faces the joint between the voltage detection element and the terminal portion for voltage detection, Have. The holding part is provided with a pressurizing part for pressing the voltage detecting element against the voltage detecting terminal part of the bus bar, and the bus bar cover is such that the pressing part presses the voltage detecting element against the voltage detecting terminal part of the bus bar. Attached to the battery group.

Further, according to still another aspect of the present invention for achieving the above object, a flat plate shape is attached to a battery group formed by stacking a plurality of cells to electrically connect electrode tabs of different cells. There is provided a method for manufacturing an assembled battery, wherein a bus bar cover formed of an insulating material, which covers the bus bar, holds a voltage detection element bonded to a voltage detection terminal of the bus bar. In the manufacturing method, when the voltage detection element is held on the bus bar cover, when the bus bar cover is attached to the battery group, the voltage detection element held on the bus bar cover is placed at the position where the voltage detection terminal is arranged. The voltage detecting element is held by the holding unit . Then, the manufacturing method, by pressing with the holding portion so as to press the voltage measuring element in the terminal portion of the voltage detection, attach the Basubakaba the battery group, the voltage detection element by pressing The voltage detecting element is bonded to the voltage detecting terminal by irradiating the laser through the opening penetrating in the thickness direction of the bus bar cover in a state of being pressed against the voltage detecting terminal.

  According to the present invention, the bus bar cover includes a holding portion that holds the voltage detection element. Then, the holding unit holds the voltage detection element at a position where the voltage detection element is arranged at the voltage detection terminal in the state where the bus bar cover is attached to the battery group. Accordingly, the voltage detection element can be arranged at the voltage detection terminal portion at the same time as the bus bar cover is attached to the battery group. Further, the bus bar cover has an opening facing the joint between the voltage detection element and the voltage detection terminal. This allows the voltage detecting element to be bonded to the voltage detecting terminal portion in the state where the bus bar cover is attached to the battery group. As a result, the voltage detection element can be bonded to the bus bar without the need to separately prepare a jig and fix the voltage detection element to the voltage detection terminal portion. Therefore, it is possible to provide an assembled battery, a busbar cover for the assembled battery, and a method of manufacturing the assembled battery, which can efficiently perform the work of attaching the voltage detection element to the busbar.

It is a perspective view which shows the assembled battery which concerns on embodiment. FIG. 2 is a perspective view showing a state where the upper stacking plate, the lower stacking plate, and the left and right side plates are disassembled from the battery pack shown in FIG. 1 to expose the entire laminated body with a bus bar cover attached. It is a perspective view which removes a bus bar cover from the laminated body shown in FIG. 2, and decomposes | disassembles and shows a laminated body into a battery group and a bus bar unit. It is a perspective view which decomposes | disassembles and shows the bus-bar unit shown by FIG. The state in which the anode side electrode tab of the first cell sub-assembly (single cells connected in parallel for every three groups) and the cathode side electrode tab of the second cell sub-assembly (single cells connected in parallel for every three groups) are joined by a bus bar is decomposed FIG. FIG. 6 (A) is a perspective view showing a state in which a pair of spacers (first spacer and second spacer) are attached to the unit cell, and FIG. 6 (B) is a pair of spacers (the first spacer and the second spacer) in the unit cell. It is a perspective view showing the state before attaching 2 spacers). It is a perspective view which shows a pair of spacer (1st spacer and 2nd spacer). FIG. 8 (A) is a perspective view showing a cross section of a main part of a state where a bus bar is joined to the electrode tabs of the stacked unit cells, and FIG. 8 (B) is a side view showing FIG. 8 (A) from the side. is there. It is the side view which expanded the area | region 9 shown in FIG.8 (B). 10 (A) is a perspective view of the bus bar holder, FIG. 10 (B) is a perspective view of the anode side bus bar and the cathode side bus bar, and FIG. 10 (C) is an enlarged view of a region 10C shown in FIG. 10 (A). 11A and 11B are perspective views of the bus bar cover. 12A is an enlarged view of a region 12A shown in FIG. 11A, FIG. 12B is an enlarged view of a region 12B shown in FIG. 11B, and FIG. 12C is a cross-sectional view taken along line 12C-12C of FIG. FIG. 13 (A) is a perspective view showing a main part when the bus bar cover is attached to the battery group, and FIG. 13 (B) is a part corresponding to a region 13B shown in FIG. 10 (C) when the bus bar cover is attached to the battery group. FIG. 13C is an enlarged view of a portion corresponding to the area 13B shown in FIG. 10C in the state where the bus bar cover is attached to the battery group. It is a front view of the battery group in the state where the bus bar cover was attached. 15A is an enlarged view of a region 15A shown in FIG. 14, and FIG. 15B is a sectional view taken along line 15B-15B of FIG. 15A. 16A is a perspective view showing a main part when the voltage detection element is held by the holding part, FIG. 16B is a bottom view of the holding part, and FIG. 16C is 16C of FIG. 16B. It is sectional drawing which follows the -16C line. It is a figure which shows the manufacturing method of the assembled battery which concerns on embodiment, Comprising: It is a perspective view which shows typically the state which has laminated | stacked the member which comprises an assembled battery with respect to a mounting base in order. FIG. 18 is a perspective view schematically showing a state where the constituent members of the battery pack are being pressed from above, following FIG. 17. FIG. 19 is a perspective view schematically showing a state where the side plate is laser-welded to the upper pressure plate and the lower pressure plate, following FIG. 18. FIG. 20 is a perspective view schematically showing a state where some members of the bus bar unit are attached to the battery group, following FIG. 19. FIG. 21 is a perspective view schematically showing the state where the bus bar of the bus bar unit is laser-welded to the electrode tabs of the unit cells, following FIG. 20. It is a side view which shows the principal part in a state where the bus bar is laser-bonded to the electrode tabs of the stacked cells. FIG. 23 is a perspective view schematically showing a state where the anode-side terminal and the cathode-side terminal are laser-welded to the anode-side bus bar and the cathode-side bus bar, following FIGS. 21 and 22. FIG. 24 is a perspective view schematically showing a state where the bus bar cover is attached to the bus bar unit, following FIG. 23. FIG. 25 is a perspective view illustrating a state where the voltage detecting element is joined to the voltage detecting terminal portion, following FIG. 24.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. The sizes and ratios of the respective members in the drawings may be exaggerated for convenience of explanation and may differ from the actual sizes and ratios. In the figure, the azimuths are indicated by the arrows indicated by X, Y, and Z. The direction of the arrow indicated by X indicates the direction that intersects the stacking direction of the unit cells 110 and that is along the longitudinal direction of the unit cells 110. The direction of the arrow indicated by Y intersects the stacking direction of the unit cells 110 and indicates the direction along the lateral direction of the unit cells 110. The direction of the arrow indicated by Z indicates the stacking direction of the unit cells 110.

  First, the assembled battery 100 of the present embodiment will be described with reference to FIGS.

  FIG. 1 is a perspective view showing an assembled battery 100 according to this embodiment. FIG. 2 is a perspective view showing a state where the upper stacking plate 151, the lower stacking plate 152, and the left and right side plates 153 are disassembled from the assembled battery 100 shown in FIG. 1 and the entire stacked body 100S with the bus bar cover 140 attached is exposed. It is a figure. FIG. 3 is a perspective view showing the bus bar cover 140 removed from the stack 100S shown in FIG. 2 and the stack 100S disassembled into a battery group 100G and a bus bar unit 130. FIG. 4 is an exploded perspective view of the bus bar unit 130 shown in FIG. FIG. 5 shows the anode-side electrode tabs 113A of the first cell sub-assembly 100M (cells 110 connected in parallel for every three groups) and the cathode-side electrode tabs 113K of the second cell sub-assembly 100N (cells 110 connected in parallel for every three groups). It is a perspective view which decomposes | disassembles and shows the state joined by the bus bar 131 typically. 6A is a perspective view showing a state where a pair of spacers 120 (first spacer 121 and second spacer 122) are attached to the unit cell 110, and FIG. 6B is a pair of spacers 120 on the unit cell 110. It is a perspective view showing the state before attaching (the 1st spacer 121 and the 2nd spacer 122). FIG. 7 is a perspective view showing a pair of spacers 120 (first spacer 121 and second spacer 122). FIG. 8 (A) is a perspective view showing a cross section of a main part of a state where the bus bar 131 is joined to the electrode tabs 113 of the stacked unit cells 110, and FIG. 8 (B) shows FIG. 8 (A) from the side. It is a side view. FIG. 9 is an enlarged side view of the area 9 shown in FIG. 10A is a perspective view of the bus bar holder 132, FIG. 10B is a perspective view of the anode side bus bar 131A and the cathode side bus bar 131K, and FIG. 10C is an enlarged view of a region 10C shown in FIG. 10A. Is. 11A and 11B are perspective views of the bus bar cover 140. 12A is an enlarged view of a region 12A shown in FIG. 11A, FIG. 12B is an enlarged view of a region 12B shown in FIG. 11B, and FIG. 12C is a cross-sectional view taken along line 12C-12C of FIG. 13A is a perspective view showing a main part when the bus bar cover 140 is attached to the battery group 100G, and FIG. 13B is an area 13B shown in FIG. 10C when the bus bar cover 140 is attached to the battery group 100G. FIG. 13C is an enlarged view of a corresponding portion, and FIG. 13C is an enlarged view of a portion corresponding to a region 13B shown in FIG. 10C in a state where the bus bar cover 140 is attached to the battery group 100G. FIG. 14 is a front view of the battery group 100G with the bus bar cover 140 attached. 15A is an enlarged view of a region 15A shown in FIG. 14, and FIG. 15B is a sectional view taken along line 15B-15B of FIG. 15A. 16A is a perspective view showing a main part when the voltage detection element 140P is held by the holding portion 140Q, FIG. 16B is a bottom view of the holding portion 140Q, and FIG. 16C is FIG. 16C is a cross-sectional view taken along line 16C-16C of FIG.

  In the state shown in FIG. 1, the left front side is referred to as the entire assembled battery 100 and the “front side” of each component, and the right rear side is referred to as the entire assembled battery 100 and the “rear side” of each component, The front side on the right side and the back side on the left side are referred to as “side sides” on the left and right of the entire assembled battery 100 and each component.

  As shown in FIGS. 1 and 2, the assembled battery 100 has a stack 100S including a battery group 100G in which a plurality of flat cells 110 are stacked in the thickness direction. The assembled battery 100 further includes a bus bar cover 140 attached to the front surface side of the stacked body 100S, a housing 150 that houses the stacked body 100S in a state in which each single cell 110 is pressed along the stacking direction of the single cells 110, Have. As shown in FIG. 3, the stacked body 100S includes a battery group 100G and a bus bar unit 130 that is attached to the front surface side of the battery group 100G and integrally holds a plurality of bus bars 131. The bus bar cover 140 covers and protects the bus bar unit 130. As shown in FIG. 4, the bus bar unit 130 includes a plurality of bus bars 131 and a bus bar holder 132 that integrally mounts the plurality of bus bars 131 in a matrix. Of the plurality of bus bars 131, the anode side terminal 133 is attached to the anode side end, and the cathode side terminal 134 is attached to the cathode side end.

  Briefly, the assembled battery 100 of the present embodiment includes a plurality of unit cells 110 each including a power generation element 111 and a flat battery body 110H and an electrode tab 113 led out from the battery body 110H. The battery group 100G is formed by stacking a plurality of electrodes, and the tip portion 113d of the electrode tab 113 is bent along the stacking direction Z of the unit cell 110. In addition, the assembled battery 100 includes a terminal portion 131d for voltage detection, is arranged so as to face the tip end portion 113d of the electrode tab 113 of a different single cell 110, and has a flat plate shape for electrically connecting the tip end portions 113d to each other. It further has a bus bar 131 and a bus bar cover 140 which is attached to the battery group 100G and is formed of an insulating material to cover the bus bar 131. The bus bar cover 140 is joined to the voltage detecting terminal portion 131d, and the voltage detecting element 140P for detecting the voltage of the unit cell 110 and the voltage detecting element 140P for detecting the voltage are attached to the battery group 100G. Holding portion 140Q that holds the voltage detecting element 140P at a position arranged in the terminal portion 131d, and the voltage detecting element 140P and the voltage detecting terminal portion 131d that are formed to penetrate in the thickness direction of the bus bar cover 140. And a third opening 140R (corresponding to an opening portion) facing the joint portion of. Hereinafter, the assembled battery 100 of this embodiment will be described in detail.

  As shown in FIG. 5, the battery group 100G includes a first cell sub-assembly 100M including three electric cells 110 electrically connected in parallel and a second cell sub-assembly 100N including three electric cells 110 electrically connected in parallel. And are connected in series by a bus bar 131.

  The first cell sub-assembly 100M and the second cell sub-assembly 100N have the same configuration except the refraction direction of the tip portion 113d of the electrode tab 113 of the unit cell 110. Specifically, the second cell sub-assembly 100N is an inverted one of the unit cells 110 included in the first cell sub-assembly 100M. However, the refraction direction of the tip portion 113d of the electrode tab 113 of the second cell sub-assembly 100N is aligned with the lower side of the stacking direction Z so as to be the same as the refraction direction of the tip portion 113d of the electrode tab 113 of the first cell sub-assembly 100M. ing. Each unit cell 110 has a pair of spacers 120 (first spacer 121 and second spacer 122) attached thereto.

  The unit cell 110 corresponds to, for example, a flat lithium ion secondary battery. As shown in FIGS. 6 and 8, the unit cell 110 is a battery body 110H in which a power generation element 111 is sealed with a pair of laminate films 112, and is electrically connected to the power generation element 111 and led out to the outside from the battery body 110H. And a thin plate-shaped electrode tab 113.

  The power generation element 111 is configured by laminating a plurality of positive and negative electrodes sandwiched by separators. The power generation element 111 is supplied with electric power from the outside and charged, and then supplies electric power while discharging to an external electric device.

  The laminate film 112 is formed by covering both sides of the metal foil with an insulating sheet. The pair of laminate films 112 covers the power generation element 111 from both sides in the stacking direction Z and seals the four sides thereof. As shown in FIG. 6, the pair of laminate films 112 lead out the anode-side electrode tab 113A and the cathode-side electrode tab 113K from the space between the one ends 112a along the lateral direction Y toward the outside.

  As shown in FIGS. 6 and 7, the laminating film 112 has a pair of connecting holes 112e provided at both ends of one end 112a along the lateral direction Y and a pair of connecting pins 121i of the first spacer 121, respectively. It is inserted. On the other hand, in the laminate film 112, the pair of connecting pins 122i are inserted into the pair of connecting holes 112e provided at both ends of the other end 112b along the lateral direction Y, respectively. The laminate film 112 is formed by bending both ends 112c and 112d along the longitudinal direction X upward in the stacking direction Z. The laminate film 112 may be formed by bending both ends 112c and 112d along the longitudinal direction X downward in the stacking direction Z.

  As shown in FIGS. 6, 8 and 9, the electrode tab 113 includes an anode-side electrode tab 113A and a cathode-side electrode tab 113K, which are separated from each other between the one end portions 112a of the pair of laminate films 112. It extends outward in the state. The anode-side electrode tab 113A is made of aluminum in accordance with the characteristics of the components on the anode side in the power generation element 111. The cathode side electrode tab 113K is made of copper in accordance with the characteristics of the cathode side constituent member in the power generation element 111.

  As shown in FIGS. 8 and 9, the electrode tab 113 is formed in an L shape from a base end portion 113c adjacent to the battery main body 110H to a tip end portion 113d. Specifically, the electrode tab 113 extends from the base end portion 113c along one of the longitudinal directions X. On the other hand, the tip portion 113d of the electrode tab 113 is bent and formed along the lower side in the stacking direction Z. The shape of the tip portion 113d of the electrode tab 113 is not limited to the L shape. The tip portion 113d of the electrode tab 113 is formed in a planar shape so as to face the bus bar 131. The electrode tab 113 may be formed in a U-shape by further extending the tip portion 113d and folding the extended portion along the base end portion 113c toward the battery main body 110H side. On the other hand, the base end portion 113c of the electrode tab 113 may be formed in a wavy shape or a curved shape.

  As shown in FIGS. 5 and 8, the tip portion 113d of each of the electrode tabs 113 is aligned and bent downward in the stacking direction Z in the single cell 110 in which a plurality of stacked sheets are stacked. Here, as shown in FIG. 5, the assembled battery 100 includes three unit cells 110 electrically connected in parallel (first cell sub-assemblies 100M) and another three unit cells 110 electrically connected in parallel (second cell). The cell subassemblies 100N) are connected in series. Therefore, the top and bottom of the unit cell 110 are replaced for each of the three unit cells 110 so that the positions of the anode-side electrode tab 113A and the cathode-side electrode tab 113K of the unit cell 110 are crossed along the stacking direction Z. There is.

  However, simply replacing the top and bottom of each of the three unit cells 110 causes the positions of the tip portions 113d of the electrode tabs 113 to vary in the vertical direction along the stacking direction Z. The tip 113d of 113 is adjusted and refracted so that the positions thereof are aligned.

  In the first cell sub-assembly 100M shown in the lower part of FIG. 5, the anode side electrode tab 113A is arranged on the right side in the figure, and the cathode side electrode tab 113K is arranged on the left side in the figure. On the other hand, in the second cell sub-assembly 100N shown in the upper part of FIG. 5, the cathode side electrode tab 113K is arranged on the right side in the figure, and the anode side electrode tab 113A is arranged on the left side in the figure.

  Thus, even if the anode-side electrode tab 113A and the cathode-side electrode tab 113K are arranged differently, the tip portion 113d of the electrode tab 113 of the unit cell 110 is bent downward along the stacking direction Z. Further, as shown in FIG. 3, the tip portion 113d of each electrode tab 113 is arranged on the same surface side of the laminated body 100S. A double-sided tape 160 is attached to the unit cells 110 located on the upper surfaces of the first cell sub-assembly 100M and the second cell sub-assembly 100N so that the double-sided adhesive tape 160 is adhered to the laminated member to be laminated above.

  The pair of spacers 120 (the first spacer 121 and the second spacer 122) are arranged between the stacked unit cells 110 as shown in FIGS. 3, 5, and 8. As shown in FIG. 6, the first spacer 121 is arranged along one end 112 a of the laminate film 112 from which the electrode tab 113 of the unit cell 110 is projected. As shown in FIG. 6, the second spacer 122 is arranged along the other end 112b of the laminate film 112. The second spacer 122 has a configuration in which the shape of the first spacer 121 is simplified. Each unit cell 110 has a pair of spacers 120 (a first spacer 121 and a second spacer 122) attached thereto, and then a plurality of cells are stacked in the stacking direction Z. The pair of spacers 120 (first spacer 121 and second spacer 122) are made of insulating reinforced plastics. Hereinafter, the configuration of the first spacer 121 will be described, and then the configuration of the second spacer 122 will be described in comparison with the configuration of the first spacer 121.

  As shown in FIGS. 6 and 7, the first spacer 121 is formed in an elongated rectangular parallelepiped shape along the lateral direction Y. The first spacer 121 includes mounting portions 121M and 121N at both ends in the longitudinal direction (transverse direction Y).

  As shown in FIG. 8B, when the first spacer 121 is stacked in a state of being attached to the unit cell 110, the first spacer 121 and the upper surfaces 121a of the mounting portions 121M and 121N of the first spacer 121 and the first spacer 121a. The lower surfaces 121b of the mounting portions 121M and 121N of the other first spacer 121 arranged above the one spacer 121 abut.

  As shown in FIGS. 7 and 8B, the first spacer 121 is provided at a position provided on the upper surface 121a of one first spacer 121 in order to perform relative positioning of the unit cells 110 that are stacked. The positioning pin 121c and the positioning hole 121d which is opened in the lower surface 121b of the other first spacer 121 and corresponds to the position of the positioning pin 121c are fitted.

  As shown in FIG. 7, the first spacer 121 has a locating hole 121e for inserting a bolt that connects a plurality of assembled batteries 100 that are connected along the stacking direction Z, and a mounting portion along the stacking direction Z. It is opened to 121M and 121N, respectively.

  As shown in FIGS. 6B and 7, the first spacer 121 is formed such that a region between the mounting portions 121M and 121N is cut out from the upper side in the stacking direction Z. The notched portion includes a first support surface 121g and a second support surface 121h along the longitudinal direction of the first spacer 121 (the short direction Y of the unit cell 110). The first supporting surface 121g is formed higher than the second supporting surface 121h in the stacking direction Z, and is located on the unit cell 110 side.

  As shown in FIG. 6, the first spacer 121 mounts and supports the one end 112a of the laminate film 112 having the electrode tab 113 projected by the first support surface 121g. The first spacer 121 includes a pair of connecting pins 121i protruding upward from both ends of the first supporting surface 121g.

  As shown in FIGS. 8 and 9, the first spacer 121 includes a support portion 121j that is in contact with the electrode tab 113 from the opposite side of the bus bar 131 to support the tip portion 113d of the electrode tab 113 of the unit cell 110. It is provided on a side surface adjacent to the support surface 121h and along the stacking direction Z. The support portion 121j of the first spacer 121 sandwiches the tip end portion 113d of the electrode tab 113 together with the bus bar 131 so that the tip end portion 113d and the bus bar 131 sufficiently come into contact with each other.

  As shown in FIGS. 6 and 7, the second spacer 122 has a configuration in which the shape of the first spacer 121 is simplified. The second spacer 122 corresponds to a configuration in which a part of the first spacer 121 is deleted along the lateral direction Y of the unit cell 110. Specifically, the second spacer 122 is configured by replacing the second support surface 121h and the first support surface 121g of the first spacer 121 with a support surface 122k. Specifically, like the first spacer 121, the second spacer 122 includes mounting portions 122M and 122N. The second spacer 122 is provided with a support surface 122k at a portion notched from the upper side in the stacking direction Z in the region between the mounting portions 122M and 122N. The support surface 122k mounts and supports the other end 112b of the laminate film 112. Like the first spacer 121, the second spacer 122 includes a positioning pin 122c, a positioning hole, a locate hole 122e, and a connecting pin 122i.

  As shown in FIGS. 3 and 4, the bus bar unit 130 integrally includes a plurality of bus bars 131. The bus bar 131 is made of a metal having conductivity, and electrically connects the tip portions 113d of the electrode tabs 113 of different unit cells 110 to each other. The bus bar 131 is formed in a flat plate shape and stands up along the stacking direction Z.

  The bus bar 131 is an anode side bus bar 131A that is laser-welded with the anode-side electrode tab 113A of one unit cell 110, and a cathode side that is laser-welded with the cathode-side electrode tab 113K of another unit cell 110 that is adjacent in the stacking direction Z. The bus bar 131K is joined and integrally configured.

  As shown in FIGS. 4 and 8, the anode-side bus bar 131A and the cathode-side bus bar 131K have the same shape and are each formed in an L shape. The anode-side bus bar 131A and the cathode-side bus bar 131K are stacked upside down. Specifically, the bus bar 131 joins the bent portion at one end of the anode side bus bar 131A along the stacking direction Z and the bent portion at one end of the cathode side bus bar 131K along the stacking direction Z, It is integrated. As shown in FIG. 4, the anode-side bus bar 131A and the cathode-side bus bar 131K include side portions 131c extending from one end in the lateral direction Y along the longitudinal direction X. The side portion 131c is joined to the bus bar holder 132.

  The anode-side bus bar 131A is made of aluminum similarly to the anode-side electrode tab 113A. The cathode side bus bar 131K is made of copper similarly to the cathode side electrode tab 113K. The anode-side bus bar 131A and the cathode-side bus bar 131K made of different metals are joined together by ultrasonic joining.

  As shown in FIG. 5, when the assembled battery 100 is formed by connecting three battery cells 110 connected in parallel to each other in series as shown in FIG. 5, the anode-side bus bar 131A is Laser welding is performed on the anode-side electrode tabs 113A of the three unit cells 110 that are adjacent to each other along the stacking direction Z. Similarly, the bus bar 131 laser-welds the cathode side bus bar 131K to the cathode side electrode tabs 113K of the three unit cells 110 that are adjacent to each other in the stacking direction Z.

  However, among the bus bars 131 arranged in a matrix, the bus bar 131 located in the upper right of the drawings in FIGS. 3 and 4 corresponds to the anode-side termination of the 21 unit cells 110 (3 parallel 7 series). It is composed of only the side bus bar 131A. The anode-side bus bar 131A is laser-bonded to the anode-side electrode tabs 113A of the uppermost three cells 110 of the battery group 100G. Similarly, among the bus bars 131 arranged in a matrix, the bus bar 131 located at the lower left of the drawings in FIGS. 3 and 4 corresponds to the cathode-side termination of the 21 unit cells 110 (3 parallel 7 series), It is composed of only the cathode side bus bar 131K. The cathode-side bus bar 131K is laser-bonded to the cathode-side electrode tabs 113K of the three lowest unit cells 110 of the battery group 100G.

  As shown in FIG. 3, the bus bar holder 132 integrally holds a plurality of bus bars 131 in a matrix shape so as to face the electrode tabs 113 of each of the stacked unit cells 110. The bus bar holder 132 is made of an insulating resin and is formed in a frame shape.

  As shown in FIG. 4, the bus bar holders 132 are arranged in a pair along the stacking direction Z so as to be positioned on both sides in the longitudinal direction of the first spacer 121 supporting the electrode tab 113 of the unit cell 110. Each of the columns 132a is provided. The pair of support columns 132a are fitted to the side surfaces of the mounting portions 121M and 121N of the first spacer 121. The pair of support columns 132a are L-shaped when viewed in the stacking direction Z, and are formed in a plate shape extending in the stacking direction Z. The bus bar holder 132 is provided with a pair of auxiliary support columns 132b which are erected in the stacking direction Z and are spaced apart from each other so as to be located near the center of the first spacer 121 in the longitudinal direction. The pair of auxiliary column parts 132b are formed in a plate shape extending along the stacking direction Z.

  As shown in FIG. 4, the bus bar holder 132 includes insulating portions 132c that project between the adjacent bus bars 131 along the stacking direction Z. The insulating portion 132c is formed in a plate shape extending along the lateral direction Y. Each of the insulating portions 132c is horizontally provided between the column portion 132a and the auxiliary column portion 132b. The insulating portion 132c prevents discharge by insulating between the bus bars 131 of the unit cells 110 that are adjacent to each other along the stacking direction Z.

  The bus bar holder 132 may be configured by joining a column portion 132a, an auxiliary column portion 132b, and an insulating portion 132c, which are independently formed, to each other, or the column portion 132a, the auxiliary column portion 132b, and an insulating portion 132c may be integrally formed. It may be formed by molding.

  As shown in FIGS. 3 and 4, the anode side terminal 133 corresponds to the anode side terminal of the battery group 100G configured by alternately stacking the first cell sub-assemblies 100M and the second cell sub-assemblies 100N.

  As shown in FIGS. 3 and 4, the anode-side terminal 133 is joined to the anode-side bus bar 131A located in the upper right of the figure among the bus bars 131 arranged in a matrix. The anode-side terminal 133 is made of a conductive metal plate, and when viewed along the lateral direction Y, the one end 133b and the other end 133c are arranged along the stacking direction Z with reference to the central part 133a. It consists of shapes that are refracted in different directions. The one end 133b is laser-bonded to the anode-side bus bar 131A. The other end 133c connects an external input / output terminal to a hole 133d (including a screw groove) opened at the center thereof.

  As shown in FIGS. 3 and 4, the cathode side terminal 134 corresponds to the cathode side end of the battery group 100G configured by alternately stacking the first cell sub-assembly 100M and the second cell sub-assembly 100N. As shown in FIGS. 3 and 4, the cathode-side terminal 134 is joined to the cathode-side bus bar 131K, which is located in the lower left part of the figure among the bus bars 131 arranged in a matrix. The cathode side terminal 134 has the same configuration as the anode side terminal 133.

  As shown in FIG. 10B, the anode-side bus bar 131A (cathode-side bus bar 131K) includes a terminal portion 131d for voltage detection. In the present embodiment, the voltage detection terminal portion 131d is formed at one end portion of both longitudinal end portions 131e of the anode side bus bar 131A (cathode side bus bar 131K). The terminal portion 131d for voltage detection has a shape extending from the end 131e in the longitudinal direction of the anode side bus bar 131A (cathode side bus bar 131K) in a state of being integrated with the anode side bus bar 131A (cathode side bus bar 131K). Equipped with.

  As shown in FIGS. 10A and 10C, the bus bar holder 132 includes a support portion 132d that supports a voltage detection terminal portion 131d included in the anode side bus bar 131A (cathode side bus bar 131K). The support portion 132d has a shape protruding from the side surface of the auxiliary column portion 132b of the bus bar holder 132 in a direction intersecting the stacking direction Z.

  The bus bar cover 140 is attached to the battery group 100G as shown in FIGS. By covering the busbar unit 130, the busbar cover 140 prevents the busbars 131 from being short-circuited with each other or the busbar 131 from being in contact with an external member to be short-circuited or to cause electric leakage. Further, the bus bar cover 140 exposes the anode side terminal 133 and the cathode side terminal 134 to the outside, and charges and discharges the power generation element 111 of each unit cell 110. The bus bar cover 140 is made of an insulating material. In the present embodiment, the bus bar cover 140 is made of insulating plastics.

  As shown in FIG. 3, the bus bar cover 140 is formed in a flat plate shape and stands up along the stacking direction Z. The bus bar cover 140 has a shape in which the upper end 140b and the lower end 140c of the side surface 140a are bent along the longitudinal direction X, and is fitted into the bus bar unit 130.

  As shown in FIGS. 2 and 3, the side surface 140a of the bus bar cover 140 is formed of a rectangular hole slightly larger than the anode side terminal 133 at a position corresponding to the anode side terminal 133 provided in the bus bar unit 130. One opening 140d is provided. Similarly, the side surface 140 a of the bus bar cover 140 has a second opening 140 e, which is a rectangular hole slightly larger than the cathode side terminal 134, at a position corresponding to the cathode side terminal 134 provided in the bus bar unit 130. .

  The bus bar cover 140 will be described in more detail with reference to FIGS. 11 to 16.

  As shown in FIGS. 11 and 12, the bus bar cover 140 has a voltage detection element 140P that detects the voltage of the unit cell 110, a holding portion 140Q that holds the voltage detection element, and a bus bar cover 140 that penetrates in the thickness direction of the bus bar cover 140. And a third opening 140R (corresponding to an opening) formed by the above. The thickness direction of the bus bar cover 140 corresponds to the longitudinal direction X of the unit cell 110 when the bus bar cover 140 is attached to the battery group 100G.

  The voltage detection element 140P is joined to the terminal portion 131d for voltage detection. In the present embodiment, the voltage detection element 140P and the voltage detection terminal portion 131d are joined by laser welding.

  As shown in FIGS. 13 and 14, the holding portion 140Q detects the voltage at the position where the voltage detecting element 140P is arranged at the voltage detecting terminal portion 131d when the bus bar cover 140 is attached to the battery group 100G. The working element 140P is held. In other words, the position where the voltage detection element 140P is arranged in the voltage detection terminal portion 131d means that the voltage detection is performed when the bus bar cover 140 is viewed in plan from the mounting direction of the bus bar cover 140 as shown in FIG. The device 140P is positioned so as to overlap the voltage detection terminal portion 131d. By attaching the bus bar cover 140 to the battery group 100G, the voltage detection element 140P is arranged in the voltage detection terminal portion 131d. Note that the side surface 140a of the bus bar cover 140 is omitted in FIGS. 13B and 13C.

  As shown in FIG. 15A, the third opening 140R faces a joint portion 140f between the voltage detection element 140P and the voltage detection terminal portion 131d. In other words, the third opening 140R is opened so that the joint portion 140f is included inside the outline of the third opening 140R when the bus bar cover 140 is viewed in plan from the mounting direction of the bus bar cover 140. There is.

  As shown in FIGS. 12C and 15B, the holding unit 140Q includes a pair of pressure units 140S that press the voltage detection element 140P against the voltage detection terminal unit 131d included in the bus bar 131.

  In the present embodiment, the holding portion 140Q is, as shown in FIGS. 12B, 12C, and 15B, a side surface 140a of the bus bar cover 140 at a position facing the voltage detection element 140P. It is provided with a pair of vertical walls 140g protruding from. The vertical wall 140g protrudes from the side surface 140a of the bus bar cover 140 toward the voltage detection terminal portion 131d of the bus bar 131 when the bus bar cover 140 is attached to the battery group 100G. The vertical wall 140g extends from the side surface 140a of the busbar cover 140 to the voltage detection terminal portion 131d of the busbar 131 when the busbar cover 140 is attached to the battery group 100G.

  In the present embodiment, the pair of pressurizing portions 140S project from the pair of vertical walls 140g in a direction toward each other, as shown in FIGS. 12 (C) and 15 (B). The pair of pressurizing portions 140S abut on the surface of the voltage detecting element 140P opposite to the surface abutting on the voltage detecting terminal portion 131d of the bus bar 131 when the bus bar cover 140 is attached to the battery group 100G. The pressure surface 140Sa is provided. The pressing surface 140Sa presses the voltage detecting element 140P toward the voltage detecting terminal portion 131d included in the bus bar 131 when the bus bar cover 140 is attached to the battery group 100G.

  In the present embodiment, as shown in FIG. 16, the holding unit 140Q includes a drop prevention unit 140U that prevents the voltage detection element 140P from falling off the holding unit 140Q. The form of the fall prevention unit 140U is not limited as long as it can prevent the voltage detection element 140P from dropping from the holding unit 140Q. In the present embodiment, the fall prevention unit 140U contacts the voltage detection element 140P and holds the voltage detection element 140P between the pressure detection element 140P and the pressurization section 140S. The voltage detecting element 140P is sandwiched between the pressurizing portion 140S and the drop-preventing portion 140U, so that the voltage-detecting element 140P is prevented from dropping from the holding portion 140Q.

  As shown in FIGS. 11 and 12, the bus bar cover 140 further includes a signal line 140T connected to the voltage detecting element 140P and transmitting a signal from the voltage detecting element 140P.

  The form of the signal line 140T is not limited as long as the signal from the voltage detection element 140P can be transmitted. In the present embodiment, the signal line 140T is a long member including a long metal member and a covering material that covers the member and is made of an insulating material.

  The form of connection between the signal line 140T and the voltage detection element 140P is not particularly limited as long as the signal line 140T can transmit a signal from the voltage detection element 140P. In the present embodiment, the signal line 140T and the voltage detection element 140P are connected via the connector 140Ta. The connector 140Ta connects the signal line 140T and the voltage detection element 140P in a conductive state.

  The signal line 140T is connected to each of the voltage detecting elements 140P. The signal lines 140T connected to each of the voltage detecting elements 140P are bundled near the center of the bus bar cover 140 in the lateral direction. The short side direction of the bus bar cover 140 corresponds to the short side direction Y of the unit cell 110 in the state where the bus bar cover 140 is attached to the battery group 100G.

  The bus bar cover 140 has a fourth opening 140h at the upper end 140b near the center of the bus bar cover 140 in the lateral direction. As shown in FIG. 14, the signal lines 140T that are bundled near the center in the lateral direction of the bus bar cover 140 pass through the fourth opening 140h from the bus bar cover 140 when the bus bar cover 140 is attached to the battery group 100G. Taken out.

  As shown in FIGS. 10A and 10B, the bus bar holder 132 includes a housing portion 132f that houses the signal line 140T included in the bus bar cover 140 when the bus bar cover 140 is attached to the battery group 100G. In the present embodiment, the housing portion 132f is formed between the pair of auxiliary column portions 132b of the bus bar holder 132.

  The accommodating portion 132f includes an opening 132g communicating with the accommodating portion 132f on a side surface of the auxiliary column portion 132b opposite to the side surface on the accommodating portion 132f side. As shown in FIGS. 13B and 13C, the signal line 140T is housed in the housing portion 132f in a state where a part of the signal line 140T is passed through the opening 132g.

  As described above, the bus bar cover 140 includes the holder 140Q that holds the voltage detecting element 140P. Then, the holding portion 140Q holds the voltage detection element 140P at the position where the voltage detection element 140P is arranged in the voltage detection terminal portion 131d when the bus bar cover 140 is attached to the battery group 100G. Accordingly, the bus bar cover 140 can be attached to the battery group 100G, and at the same time, the voltage detection element 140P can be arranged in the voltage detection terminal portion 131d. Further, the bus bar cover 140 is provided with a third opening 140R that faces a joint portion 140f between the voltage detection element 140P and the voltage detection terminal portion 131d. This allows the voltage detection element 140P to be bonded to the voltage detection terminal portion 131d in a state where the bus bar cover 140 is attached to the battery group 100G. As a result, the voltage detection element 140P can be bonded to the bus bar 131 without the need to separately prepare a jig and fix the voltage detection element 140P to the voltage detection terminal portion 131d.

  Further, as described above, the tip portion 113d of the electrode tab 113 is bent along the stacking direction Z of the unit cell 110. As a result, the shape of the bus bar 131 that electrically connects the tip portions 113d of the electrode tabs 113 can be made flat. Specifically, the tip portion 113d of the electrode tab 113 and the bus bar 131 are preferably in surface contact with each other to facilitate the flow of current between the tip portion 113d of the electrode tab 113 and the bus bar 131. However, in the battery group 100G in which a plurality of unit cells 110 are stacked in the thickness direction, if the tip portion 113d of the electrode tab 113 is not bent along the stacking direction Z of the unit cells 110, the electrodes must be bent unless the bus bar 131 is bent. The tip portion 113d of the tab 113 and the bus bar 131 cannot be brought into surface contact with each other.

  On the other hand, in the present embodiment, the tip portion 113d of the electrode tab 113 is bent along the stacking direction Z of the unit cell 110, so that the tip portion 113d of the electrode tab 113 is in surface contact without bending the bus bar 131. Can be made. This allows the bus bar 131 to have a flat plate shape. As a result, the voltage detecting terminal portion 131d is extended from the longitudinal end portion 131e of the bus bar 131 so that the area of the surface of the voltage detecting terminal portion 131d that abuts the voltage detecting element 140P becomes larger. It will be easier. By increasing the area of the surface of the voltage detection terminal portion 131d that is in contact with the voltage detection element 140P, it becomes easier to dispose the voltage detection element 140P on the voltage detection terminal portion 131d.

  In addition, as described above, the holding unit 140Q includes the pressing unit 140S that presses the voltage detection element 140P against the voltage detection terminal unit 131d included in the bus bar 131. Thereby, when the voltage detection element 140P is bonded to the bus bar 131, the voltage detection element 140P can be sufficiently brought into contact with the bus bar 131. Therefore, the joint quality between the voltage detection element 140P and the bus bar 131 is improved.

  Further, as described above, the bus bar cover 140 further includes the signal line 140T connected to the voltage detection element 140P and transmitting the signal from the voltage detection element 140P. As a result, the bus bar cover 140 can be attached to the assembled battery 100, and at the same time, the wiring of the signal line 140T for transmitting the signal from the voltage detection element 140P can be completed.

  As shown in FIGS. 1 and 2, the housing 150 accommodates the battery group 100G in a pressed state along the stacking direction. The upper pressure plate 151 and the lower pressure plate 152 sandwich and press the power generation element 111 of each of the cells 110 included in the battery group 100G to apply an appropriate surface pressure to the power generation element 111.

  As shown in FIGS. 1 and 2, the upper pressure plate 151 is arranged above the battery group 100G in the stacking direction Z. The upper pressing plate 151 has a pressing surface 151a protruding downward along the stacking direction Z at the center. The pressing surface 151a presses the power generation element 111 of each unit cell 110 downward. The upper pressure plate 151 includes holding portions 151b extending along the longitudinal direction X from both sides along the lateral direction Y. The holding portion 151b covers the placement portions 121M and 121N of the first spacer 121 or the placement portions 122M and 122N of the second spacer 122. A locating hole 151c communicating with the positioning hole 121d of the first spacer 121 or the positioning hole 122d of the second spacer 122 along the stacking direction Z is opened at the center of the holding portion 151b. A bolt that connects the battery packs 100 together is inserted into the locate hole 151c. The upper pressure plate 151 is made of a metal plate having a sufficient thickness.

  As shown in FIGS. 1 and 2, the lower pressure plate 152 has the same configuration as the upper pressure plate 151, and the top and bottom of the upper pressure plate 151 are reversed. The lower pressing plate 152 is arranged below the battery group 100G in the stacking direction Z. The lower pressing plate 152 presses the power generation element 111 of each unit cell 110 upward by the pressing surface 151a protruding upward along the stacking direction Z.

  As shown in FIGS. 1 and 2, the pair of side plates 153 has an upper portion so that the upper pressure plate 151 and the lower pressure plate 152, which press the battery group 100G from above and below in the stacking direction Z, are not separated from each other. The relative positions of the pressure plate 151 and the lower pressure plate 152 are fixed. The side plate 153 is made of a rectangular metal plate and stands up along the stacking direction Z. The pair of side plates 153 are joined to the upper pressure plate 151 and the lower pressure plate 152 by laser welding from both sides in the lateral direction Y of the battery group 100G. Each side plate 153 is seam-welded or spot-welded along the longitudinal direction X with respect to a portion of the upper end 153a that is in contact with the upper pressure plate 151. Similarly, each side plate 153 is seam welded or spot welded along the longitudinal direction X with respect to the portion of the lower end 153b in contact with the lower pressure plate 152. The pair of side plates 153 covers and protects both sides of the battery group 100G in the lateral direction Y.

  Next, a method for manufacturing the assembled battery 100 will be described with reference to FIGS.

  The manufacturing method (manufacturing process) of the assembled battery 100 includes a stacking process of stacking members constituting the assembled battery 100 (FIG. 17), a pressing process of pressing the battery group 100G of the assembled battery 100 (FIG. 18), and a side plate 153. A first joining step of joining the upper pressure plate 151 and the lower pressure plate 152 (FIG. 19), a second joining step of joining the bus bar 131 to the electrode tab 113 of the unit cell 110 and also joining the terminal to the bus bar 131 (FIG. 20 to 23), a step of holding the voltage detection element 140P on the busbar cover 140, a mounting step of attaching the busbar cover 140 to the busbar 131 (FIG. 24), and a terminal for voltage detection of the voltage detection element 140P of the busbar 131. The step (FIG. 25) of joining to the portion 131d is provided.

  The stacking step of stacking the members forming the assembled battery 100 will be described with reference to FIG.

  FIG. 17 is a diagram showing the method of manufacturing the assembled battery 100 according to the present embodiment, and is a perspective view schematically showing a state in which the members constituting the assembled battery 100 are sequentially stacked on the mounting table 701. is there.

  The mounting table 701 used in the stacking step is formed in a plate shape and is provided along a horizontal plane. The mounting table 701 is a locating pin for positioning the lower pressure plate 152, the first cell sub-assembly 100M, the second cell sub-assembly 100N, and the upper pressure plate 151, which are stacked in order, so as to align the relative positions of the upper pressure plate 151 in the longitudinal direction X and the lateral direction Y. 702. Four locate pins 702 are erected on the upper surface 701a of the mounting table 701 at predetermined intervals. The distance between the four locate pins 702 corresponds to the distance between the locate holes 152c provided at the four corners of the upper pressure plate 151, for example. The members constituting the battery pack 100 are stacked using a robot arm, a hand lifter, a vacuum suction type collet, and the like.

  In the stacking step, as shown in FIG. 17, the robot arm mounts the lower pressure plate 152 while lowering it along the stacking direction Z in a state where the locate holes 152c provided at the four corners thereof are inserted into the locate pins 702. The table 701 is placed on the upper surface 701a. Next, the robot arm descends the first cell sub-assembly 100M along the stacking direction Z in a state where the locate holes provided in the first spacer 121 and the second spacer 122 of the constituent members are inserted into the locate pin 702. , And laminated on the lower pressure plate 152. Similarly, the robot arm alternately stacks three sets of the second cell sub-assemblies 100N and the first cell sub-assemblies 100M. A double-sided tape 160 is attached to the upper surfaces of the first cell sub-assembly 100M and the second cell sub-assembly 100N so as to adhere to a laminated member to be laminated thereabove. Then, the robot arm stacks the upper pressure plate 151 on the first cell sub-assembly 100M while lowering it along the stacking direction Z with the locate holes 151c provided at the four corners being inserted into the locate pins 702.

  A pressurizing step of pressurizing the battery group 100G of the assembled battery 100 will be described with reference to FIG.

  18 is a perspective view schematically showing a state where the constituent members of the battery pack 100 are being pressed from above, following FIG.

  The pressurizing jig 703 used in the pressurizing step includes a pressurizing portion 703a formed in a plate shape and provided along a horizontal plane, and a support portion 703b formed in a cylindrical shape and erected on the upper surface of the pressurizing portion 703a. I have it. The support portion 703b connects an electric stage and a hydraulic cylinder that are driven along the stacking direction Z. The pressing unit 703a moves downward and upward along the stacking direction Z via the support unit 703b. The pressurizing unit 703a pressurizes the abutting laminated member.

  In the pressurizing step, as shown in FIG. 18, the pressurizing unit 703a of the pressurizing jig 703 is driven by the electric stage connected to the supporting unit 703b to contact the upper pressurizing plate 151 and move in the stacking direction Z. It descends along the bottom. The upper pressure plate 151 pressed downward and the lower pressure plate 152 mounted on the mounting table 701 sandwich and pressurize the battery group 100G. An appropriate surface pressure is applied to the power generation element 111 of each unit cell 110 included in the battery group 100G. The pressurizing step is continued until the next first joining step is completed.

  A first joining step of joining the side plate 153 to the upper pressure plate 151 and the lower pressure plate 152 will be described with reference to FIG.

  19 is a perspective view schematically showing the state where the side plate 153 is laser-welded to the upper pressure plate 151 and the lower pressure plate 152, following FIG.

  The pressing plate 704 used in the first joining step presses the side plate 153 against the upper pressure plate 151 and the lower pressure plate 152, and brings the side plate 153 into close contact with the upper pressure plate 151 and the lower pressure plate 152, respectively. The push plate 704 is made of metal and has a long plate shape. The push plate 704 has a linear slit 704b opened in the main body 704a along the longitudinal direction. The push plate 704 is erected in the lateral direction along the stacking direction Z. The pressing plate 704 presses the side plate 153 by the main body 704a, while passing the laser light L1 for welding through the slit 704b.

  The laser oscillator 705 is a light source that joins the side plate 153 to the upper pressure plate 151 and the lower pressure plate 152. The laser oscillator 705 is composed of, for example, a YAG (yttrium aluminum garnet) laser. The laser beam L1 derived from the laser oscillator 705 irradiates the upper end 153a and the lower end 153b of the side plate 153 in a state where the optical path is adjusted by, for example, an optical fiber or a mirror and the light is condensed by a condenser lens. The laser beam L1 derived from the laser oscillator 705 may be branched by, for example, a half mirror, and the upper end 153a and the lower end 153b of the side plate 153 may be simultaneously irradiated.

  In the first bonding step, as shown in FIG. 19, the laser oscillator 705 horizontally scans the upper end 153a of the side plate 153 pressed by the pressing plate 704 with the laser beam L1 via the slit 704b of the pressing plate 704. Then, the side plate 153 and the upper pressure plate 151 are joined by seam welding at a plurality of locations. Similarly, the laser oscillator 705 horizontally scans the lower end 153b of the side plate 153 pressed by the pressing plate 704 with the laser light L1 through the slit 704b of the pressing plate 704, and the side plate 153 and the lower pressure plate 152 are scanned. Join by seam welding at multiple points.

  A second joining step of joining the bus bar 131 to the electrode tab 113 of the unit cell 110 and joining the terminal to the bus bar 131 will be described with reference to FIGS.

  20 is a perspective view schematically showing a state in which some members of the bus bar unit 130 are attached to the battery group 100G, following FIG. FIG. 21 is a perspective view schematically showing the state where the bus bar 131 of the bus bar unit 130 is laser-welded to the electrode tab 113 of the unit cell 110, following FIG. FIG. 22 is a side view showing a cross section of a main part of a state where the bus bar 131 is laser-bonded to the electrode tab 113 of the stacked unit cells 110. 23 is a perspective view schematically showing the state where the anode side terminal 133 and the cathode side terminal 134 are laser-welded to the anode side bus bar 131A and the cathode side bus bar 131K, following FIGS. 21 and 22.

  In the second bonding step, as shown in FIGS. 19 to 20, the mounting table 701 rotates 90 ° counterclockwise in the figure to bring the electrode tab 113 of the battery group 100G and the laser oscillator 705 to face each other. Further, the bus bar holder 132, in which the respective bus bars 131 are integrally held, is kept pressed by the robot arm while being brought into contact with the corresponding electrode tab 113 of the battery group 100G. Further, as shown in FIGS. 21 and 22, the laser oscillator 705 irradiates the bus bar 131 with the laser beam L1 to join the bus bar 131 and the tip portion 113d of the electrode tab 113 by seam welding or spot welding. After that, as shown in FIG. 23, the anode-side terminal 133 is joined to the anode-side bus bar 131A (upper right in FIG. 4) corresponding to the anode-side termination of the bus bars 131 arranged in a matrix. Similarly, the cathode-side terminal 134 is joined to the cathode-side bus bar 131K (lower left in FIG. 4) corresponding to the cathode-side termination of the bus bars 131 arranged in a matrix.

  In the step of holding the voltage detecting element 140P joined to the voltage detecting terminal portion 131d of the bus bar 131, when the bus bar cover 140 is attached to the battery group 100G, the voltage detecting element 140P held in the bus bar cover 140 is operated by the voltage detecting element 140P. The voltage detection element 140P is held at a position arranged in the detection terminal portion 131d (see FIGS. 13 and 14).

  A mounting process of attaching the bus bar cover 140 to the bus bar 131 will be described with reference to FIG.

  FIG. 24 is a perspective view schematically showing the state where the bus bar cover 140 is attached to the bus bar unit 130, following FIG. 23.

  In the mounting process, the bus arm cover 140 is attached to the bus bar unit 130 using the robot arm while fitting the upper end 140b and the lower end 140c of the bus bar cover 140 into the bus bar unit 130. The upper end 140b and the lower end 140c of the bus bar cover 140 may be joined to the bus bar unit 130 with an adhesive. The bus bar cover 140 exposes the anode side terminal 133 from the first opening 140d and the cathode side terminal 134 from the second opening 140e. The busbar unit 140 is covered with the busbar cover 140 to prevent the busbars 131 from being short-circuited with each other, and the busbar 131 from being in contact with an external member to cause short-circuiting or leakage.

  A process of joining the voltage detecting element 140P to the voltage detecting terminal portion 131d will be described with reference to FIG.

  FIG. 25 is a perspective view showing a state where the voltage detecting element 140P is joined to the voltage detecting terminal portion 131d, following FIG.

  In the step of joining the voltage detecting element 140P to the voltage detecting terminal portion 131d, laser light is emitted through the third opening 140R penetrating in the thickness direction of the bus bar cover 140 with the bus bar cover 140 attached to the battery group 100G. Thus, the voltage detecting element 140P is bonded to the voltage detecting terminal portion 131d. This allows the voltage detection element 140P to be bonded to the voltage detection terminal portion 131d in a state where the bus bar cover 140 is attached to the battery group 100G. The assembled battery 100, which has been manufactured, is removed from the mounting table 701 and carried out to an inspection process for inspecting battery performance and the like.

  The manufacturing method of the assembled battery 100 described with reference to FIGS. 17 to 25 is an automatic machine that controls overall steps by a controller, a semi-automatic machine in which an operator takes part of the steps, or a manual in which the operator takes overall steps. It may be embodied in any form of machine.

  The assembled battery 100, the assembled battery bus bar cover 140, and the method for manufacturing the assembled battery 100 according to the present embodiment described above have the following effects.

  The assembled battery 100 and the method of manufacturing the assembled battery 100 according to the present embodiment include a unit cell 110 including a battery body 110H that includes a power generation element 111 and is formed in a flat shape, and an electrode tab 113 led out from the battery body 110H. The battery group 100G is formed by stacking a plurality of sheets in the thickness direction, and the tip portion 113d of the electrode tab 113 is bent along the stacking direction Z of the unit cell 110. Further, the battery pack 100 and the method for manufacturing the battery pack 100 are provided with the terminal portion 131d for voltage detection, and are arranged so as to face the tip end portions 113d of the electrode tabs 113 of different unit cells 110, and the tip end portions 113d are electrically connected to each other. And a bus bar cover 140 that is attached to the battery group 100G and that is formed of an insulating material that covers the bus bar 131. The bus bar cover 140 is joined to the voltage detecting terminal portion 131d, and the voltage detecting element 140P for detecting the voltage of the unit cell 110 and the voltage detecting element 140P for detecting the voltage are attached to the battery group 100G. Holding portion 140Q that holds the voltage detecting element 140P at a position arranged in the terminal portion 131d, and the voltage detecting element 140P and the voltage detecting terminal portion 131d that are formed to penetrate in the thickness direction of the bus bar cover 140. And a third opening 140R that faces the joint portion of.

  According to the assembled battery 100 and the method of manufacturing the assembled battery 100 configured as above, the bus bar cover 140 includes the holding portion 140Q that holds the voltage detection element 140P. Then, the holding portion 140Q holds the voltage detection element 140P at the position where the voltage detection element 140P is arranged in the voltage detection terminal portion 131d when the bus bar cover 140 is attached to the battery group 100G. Accordingly, the bus bar cover 140 can be attached to the battery group 100G, and at the same time, the voltage detection element 140P can be arranged in the voltage detection terminal portion 131d. Further, the bus bar cover 140 is provided with a third opening 140R that faces a joint portion 140f between the voltage detection element 140P and the voltage detection terminal portion 131d. This allows the voltage detection element 140P to be bonded to the voltage detection terminal portion 131d in a state where the bus bar cover 140 is attached to the battery group 100G. As a result, the voltage detection element 140P can be bonded to the bus bar 131 without the need to separately prepare a jig and fix the voltage detection element 140P to the voltage detection terminal portion 131d. Therefore, it is possible to provide a battery pack and a method of manufacturing the battery pack that can efficiently attach the voltage detecting element to the bus bar.

  In addition, in the battery pack 100 according to the present embodiment, the holding unit 140Q includes a pressurizing unit 140S that presses the voltage detecting element 140P against the bus bar 131.

  According to the assembled battery 100 configured in this manner, when the voltage detecting element 140P is joined to the bus bar 131, the voltage detecting element 140P can be sufficiently brought into contact with the bus bar 131. As a result, the joint quality between the voltage detecting element 140P and the bus bar 131 is improved. Therefore, the voltage detection element can be reliably attached to the bus bar.

  In addition, in the battery pack 100 according to the present embodiment, the bus bar cover 140 further includes a signal line 140T that is connected to the voltage detection element 140P and that transmits a signal from the voltage detection element 140P.

  According to the assembled battery 100 configured in this manner, the wiring of the signal line 140T for transmitting the signal from the voltage detection element 140P can be completed at the same time when the bus bar cover 140 is attached to the assembled battery 100. As a result, the work of attaching the voltage detection element to the bus bar can be performed more efficiently.

  In addition, the bus bar cover 140 according to the present embodiment is attached to the battery group 100G formed by stacking a plurality of unit cells 110 and covers the flat plate-shaped bus bar 131 that electrically connects the electrode tabs 113 of different unit cells 110. A bus bar cover 140 for an assembled battery formed of an insulating material. The bus bar cover 140 according to the present embodiment is joined to the voltage detection terminal portion 131d included in the bus bar 131, and is attached to the voltage detection element 140P that detects the voltage of the unit cell 110 and the battery group 100G. The holding unit 140Q holds the voltage detection element 140P at a position where the voltage detection element 140P is arranged in the voltage detection terminal portion 131d. The bus bar cover 140 according to the present embodiment further includes a third opening 140R that is formed so as to penetrate in the thickness direction of the bus bar cover 140 and that faces the joint portion 140f between the voltage detection element 140P and the voltage detection terminal portion 131d.

  According to the bus bar cover 140 configured in this way, the bus bar cover 140 includes the holding portion 140Q that holds the voltage detection element 140P. Then, the holding portion 140Q holds the voltage detection element 140P at the position where the voltage detection element 140P is arranged in the voltage detection terminal portion 131d when the bus bar cover 140 is attached to the battery group 100G. Accordingly, the bus bar cover 140 can be attached to the battery group 100G, and at the same time, the voltage detection element 140P can be arranged in the voltage detection terminal portion 131d. Further, the bus bar cover 140 is provided with a third opening 140R which faces a joint between the voltage detecting element 140P and the voltage detecting terminal portion 131d. This allows the voltage detection element 140P to be bonded to the voltage detection terminal portion 131d in a state where the bus bar cover 140 is attached to the battery group 100G. Therefore, the voltage detection element 140P can be bonded to the bus bar 131 without the need to separately prepare a jig and fix the voltage detection element 140P to the voltage detection terminal portion 131d. Therefore, it is possible to provide the bus bar cover for the assembled battery that can efficiently perform the work of attaching the voltage detecting element to the bus bar.

  Although the assembled battery, the bus bar cover for the assembled battery, and the method for manufacturing the assembled battery have been described above through the embodiments, the present invention is not limited to the configurations described in the embodiments and is based on the description of the claims. Can be changed as appropriate.

100 sets of batteries,
100S laminate,
100G battery group,
100M 1st cell sub-assembly,
100N 2nd cell sub-assembly,
110 cells,
110H battery body,
111 power generation element,
112 laminated film,
113 electrode tab,
113A anode side electrode tab,
113K cathode side electrode tab,
113c base end,
113d tip,
120 a pair of spacers 121, 321 first spacers,
122, 222 second spacers,
130 bus bar units,
131 Bus bar,
131A Anode-side bus bar (first bus bar),
131K cathode side bus bar (second bus bar),
132 Bus bar holder,
133 Anode side terminal,
134 cathode side terminal,
140 bus bar cover,
140P voltage detection element,
140Q holding part,
140R third opening (opening),
140S pressure part,
140T signal line,
150 housing,
151 upper pressure plate,
152 lower pressure plate,
153 side plate,
153a upper end,
153b lower end,
160 double-sided tape,
701 table,
702 Locate pin,
703 pressure jig,
704 push plate,
705 laser oscillator,
L1 laser light,
X longitudinal direction (of the cell 110, which intersects the stacking direction of the cell 110)
Y (the direction intersecting the stacking direction of the unit cells 110 and the short side direction of the unit cells 110),
Z Stacking direction (of the unit cell 110).

Claims (5)

A plurality of unit cells each having a flat battery body including a power generation element and an electrode tab led out from the battery body are laminated in a thickness direction, and a tip portion of the electrode tab is a unit cell of the unit cell. A group of batteries that are bent along the stacking direction,
With a terminal portion for voltage detection, arranged so as to face the tip portion of the electrode tab of the different cells, and a flat plate-shaped bus bar for electrically connecting the tip portions,
A bus bar cover attached to the battery group and formed of an insulating material for covering the bus bar,
The bus bar cover is joined to the terminal portion for voltage detection, the voltage detection element for detecting the voltage of the unit cell, and the voltage detection element in the state of being attached to the battery group, the voltage detection element A holding portion that holds the voltage detecting element at a position arranged in the terminal portion of the bus bar cover, and a joining portion that is formed so as to penetrate in the thickness direction of the bus bar cover and that joins the voltage detecting element and the voltage detecting terminal portion possess an opening, the facing,
The holding portion includes a pressurizing portion for pressing the voltage detection element to the voltage detection terminal portion of the bus bar,
The bus bar cover is an assembled battery mounted on the battery group such that the pressurizing unit presses the voltage detection element against the voltage detection terminal of the bus bar . The holding portion includes a pair of vertical walls protruding from a side surface of the bus bar cover at positions facing each other with the voltage detection element interposed therebetween,
The pressurizing portion projects from the pair of vertical walls in a direction approaching each other, and in the voltage detecting element, contacts the voltage detecting terminal portion included in the bus bar in a state where the bus bar cover is attached to the battery group. The assembled battery according to claim 1 , further comprising a pressurizing surface that abuts a surface opposite to the contacting surface .   The battery pack according to claim 1 or 2, wherein the bus bar cover further includes a signal line that is connected to the voltage detection element and transmits a signal from the voltage detection element. A busbar cover for an assembled battery formed of an insulating material, which is attached to a battery group formed by stacking a plurality of single cells and covers a flat plate-shaped busbar that electrically connects electrode tabs of different single cells. hand,
A voltage detection element that is joined to a voltage detection terminal portion included in the bus bar and that detects the voltage of the unit cell,
In a state of being attached to the battery group, a holding portion that holds the voltage detection element at a position where the voltage detection element is arranged in the voltage detection terminal portion,
Formed therethrough in a thickness direction of the Basubakaba, have a, an opening facing the joint between the voltage terminal portions for the voltage detection and the detection element,
The holding portion includes a pressurizing portion for pressing the voltage detection element to the voltage detection terminal portion of the bus bar,
A bus bar cover for assembled batteries , which is attached to the battery group such that the pressurizing unit presses the voltage detection element against the voltage detection terminal of the bus bar . A bus bar cover formed of an insulating material is attached to a battery group formed by stacking a plurality of unit cells to cover a flat plate-shaped bus bar that electrically connects electrode tabs of different unit cells, and the voltage detection of the bus bar is performed. Hold the voltage detection element bonded to the terminal part for
When holding the voltage detecting element on the bus bar cover, when the bus bar cover is attached to the battery group, the voltage detecting element held on the bus bar cover is arranged at the terminal portion for voltage detection. In, the voltage detection element is held by a holding unit ,
Said voltage detection element by pressing with the holding portion so as to press the terminal portion for the voltage detection, Attach the Basubakaba to the cell group, the voltage detection element by the pressing In a state of being pressed against the voltage detecting terminal portion, by irradiating a laser through an opening penetrating in the thickness direction of the bus bar cover, the voltage detecting element is joined to the voltage detecting terminal portion, an assembled battery Manufacturing method.