JP2014022237A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent harmful influences such as the deformation of an electrode insulation separator due to heat generation from the electrode tabs of a unit cell while maintaining a unit cell laminated structure, thereby retaining insulation between the electrode tabs over a long period.SOLUTION: A battery pack comprises: a cell laminate 9 composed of a plurality of plate-like unit cells 1 which are laminated one on top of another, each having a cathode electrode tab 3A and an anode electrode tab 3B; bus bars 5 connected to the electrode tabs 3 of the unit cells 1 constituting the cell laminate 9 and thereby connecting the unit cells 1 together; and an electrode insulation separator 6 disposed between the bus bars 5 connected to each of the opposed electrode tabs 3 of the laminated unit cells 1 and insulating the bus bars 5 having a voltage difference from each other. The electrode insulation separator 6 is disposed in place without being connected to the bus bars 5 and the electrode tabs 3.

Description

  The present invention relates to a battery pack in which a plurality of unit cells are stacked to form a battery stack.

  The battery pack can increase the output voltage by increasing the number of batteries connected in series. For this reason, battery packs used in applications requiring high output, for example, electric bicycles, electric tools, electric cars, hybrid cars, and the like, connect a plurality of unit cells in series to increase the output. Moreover, if a unit cell excellent in space efficiency is used as the battery to be stacked, a battery pack having a large capacity can be realized as a battery pack in which a large number of unit cells are stacked while keeping the outer shape relatively small. (See Patent Document 1)

JP 2011-198660 A

  The battery pack of Patent Document 1 is shown in FIGS. 1 and 2. In this battery pack, a plurality of unit cells 201 are stacked in the thickness direction to form a battery stack 209, a pair of end plates 204 are disposed on the end surfaces in the stacking direction, and the battery stack 209 is fixed in a stacked state. . The electrode tab 203 protruding from each unit cell 201 in the direction of the laminated surface is provided with a bent piece 203A by bending the tip at a right angle. The unit cell 201 is stacked in such a manner that the adjacent electrode tabs 203 stacked adjacent to each other are connected in series, and the bent pieces 203A of the positive and negative electrode tabs 203 are stacked, and the stacked portion is connected to the bus bar 205. And a nut 208, and a set screw 207 is screwed to connect the electrode tabs 203 of the unit cells 201 stacked adjacent to each other.

  In the above battery pack, the nut 208 is disposed inside the U-shaped electrode tab 203, and thus the nut 208 is fixed to the insulating holder 206 in order to place the nut 208 in a fixed position. The insulating holder 206 is inserted into the inside of the U-shaped electrode tab 203 as an elongated rod shape, and the nut 208 is disposed at a fixed position. Further, the plurality of insulating holders 206 are connected at the ends so that the insulating holders 206 can be inserted into the U-shaped electrode tab 203 together.

  In this battery pack, the nut 208 is placed in a fixed position by the insulating holder 206, so that the set screw 207 is screwed into the nut 208 through the bus bar 205 and the bent piece 203A on which the electrode tab 203 is laminated. The unit cells 201 can be connected in series. However, in this structure, since the nut 208 is fixed to the insulating holder 206 by a method such as insert molding, the insulating holder 206 is easily deformed by the heat conducted from the electrode tab 203. In other words, it is difficult to reliably maintain the electrode tab 203 in an insulated state for a long period of time.

  The present invention has been developed for the purpose of solving the above-mentioned drawbacks. An important object of the present invention is a structure in which unit cells are stacked, and it can prevent adverse effects such as deformation of the electrode insulation separator due to heat generation of the electrode tabs of the unit cells, and can maintain insulation between the electrode tabs for a long period of time. The object is to provide a highly safe battery pack.

Means for Solving the Problems and Effects of the Invention

The battery pack of the present invention has the following configuration in order to achieve the above-described object.
The battery pack includes a battery laminate 9 formed by laminating a plurality of plate-like unit cells 1 each having a positive electrode tab 3A and a negative electrode tab 3B, and an electrode tab 3 of the unit cell 1 constituting the battery laminate 9. Are connected between the bus bar 5 connected to the unit cell 1 and the bus bar 5 connected to the opposing electrode tab 3 of the stacked unit cell 1, and the bus bars 5 having a voltage difference are connected to each other. The electrode insulation separator 6 is disposed in an unconnected state with the bus bar 5 and the electrode tab 3.

  The above battery pack has a structure in which unit cells are stacked, while increasing capacity with respect to volume while preventing adverse effects such as deformation of the electrode insulation separator due to heat generation of the electrode tabs of the unit cells and insulating between the electrode tabs. To ensure high safety over a long period of time. This is because the above-described battery pack is in an unconnected state between the bus bar and the electrode tab, with the electrode insulating separator disposed between the bus bars stacked and connected to the opposing electrode tabs of the adjacent unit cells. It is. The electrode insulation separator disposed between the bus bars with a voltage difference ensures insulation of the electrode tabs, and the electrode insulation separator not connected to both the electrode tabs and the bus bar prevents heat conduction from the electrode tabs that generate heat. Less. For this reason, harmful effects such as thermal deformation of the electrode insulating separator can be reliably prevented, and the electrode tab can be insulated in a preferable state for a long period of time.

  In the battery pack of the present invention, the unit cell 1 has a planar main surface 1A and a rectangular outer shape, and a positive electrode tab 3A and a negative electrode tab 3B are arranged on one side of the square, The positive and negative electrode tabs 3 are located in a plane parallel to the stacking surface and protrude from the outer periphery, and the electrode tabs 3A of the positive electrodes of the respective unit cells 1 are arranged in a line apart in the stacking direction of the unit cells 1. Furthermore, the negative electrode tabs 3B can be arranged in one row apart in the stacking direction, and the positive electrode tabs 3A and the negative electrode tabs 3B can be arranged in two rows. Further, the battery pack has a step bent portion 5C in the middle so that the bus bar 5 connects both ends to the positive and negative electrode tabs 3 of the adjacent unit cell 1, and one end of the step bent portion 5C. The positive electrode connecting portion 5A connected to the positive electrode tab 3A of the unit cell 1 is connected to the part, and the negative electrode connecting portion 5B connected to the negative electrode tab 3B of the unit cell 1 is connected to the other end. The positive electrode connecting portion 5A is connected to the positive electrode tab 3A of the unit cell 1 and the negative electrode connecting portion 5B is connected to the negative electrode tab 3B of the unit cell 1, and the bus bar 5 is adjacently stacked. Can be connected in series.

  The above battery pack can achieve high safety by reliably ensuring insulation between the electrode tabs while connecting a plurality of stacked unit cells in series with a bus bar to increase output. That is, the above battery pack is laminated in a state in which the electrode tabs of each unit cell are arranged in a plane parallel to the battery lamination surface, and the positive electrode tab and the negative electrode tab are arranged in two rows, Further, the bus bar is provided with a step bent portion in the middle, and a positive electrode connecting portion is provided at one end of the step bent portion, and a negative electrode connecting portion is provided at the other end. Is connected to the electrode tab of the positive electrode, the connecting portion of the negative electrode is connected to the electrode tab of the negative electrode, the adjacent stacked unit cells are connected in series, and further, the stacked and adjacent electrode tabs of the adjacent unit cells are connected to each other. This is because the electrode insulation separator disposed between the bus bars connected to each other is not connected to the bus bar and the electrode tab. In particular, in the above battery pack, the electrode tab and the bus bar of the unit cell are arranged in a plane parallel to the battery stacking surface to connect the stacking portions, and further, the voltage difference between the battery pack is arranged in a posture parallel to the stacking surface. Between a certain bus bar, an electrode insulation separator is arrange | positioned in the state which is not connected to both an electrode tab and a bus bar. For this reason, while the electrode tab is securely insulated by the electrode insulation separator, the electrode insulation separator that is not connected to both the electrode tab and the bus bar reduces heat conduction from the electrode tab that generates heat, and the electrode insulation separator is thermally deformed. Thus, the electrode tab can be insulated in a preferable state over a long period of time.

In the battery pack of the present invention, a plurality of through holes 3x and 5x are provided in the electrode tab 3 of the unit cell 1 and the positive electrode connecting portion 5A and the negative electrode connecting portion 5B of the bus bar 5, respectively. The electrode tab 3 is fixed and electrically connected to the bus bar 5 with a set screw 7 inserted into the hole 3x and the through hole 5x of the bus bar 5, and the electrode tab 3 of the adjacent unit cell 1 is connected to the bus bar. The set screws 7 fixed to 5 can be arranged while being displaced in the direction parallel to the laminated surface of the unit cells 1.
The above battery pack has a structure in which the electrode tab is fixed to the bus bar with a set screw, so that the electrode tab can be electrically connected to the bus bar in a stable and low resistance state, and is also set apart from the battery stacking direction. Therefore, there is a feature that the set screws can be insulated in an ideal state without narrowing the stacking interval of the unit cells without approaching the set screws having a voltage difference.

In the battery pack of the present invention, the electrode insulating separator 6 can have storage portions 6 a and 6 b formed of through holes or recesses for guiding the set screw 7.
In the above battery pack, the set screw is placed in the electrode insulation separator housing, so a thick electrode insulation separator with excellent insulation performance is placed between the opposing bus bars to ensure that the bus bars with a voltage difference are connected to each other. Can be insulated.

In the battery pack of the present invention, the bus bar 5 has a female screw hole 16 into which a set screw 7 is screwed, and the electrode tab 3 is fixed to the bus bar 5 by screwing the set screw 7 into the female screw hole 16. Can do.
The above battery pack can be electrically connected by securely laminating the electrode tab to the bus bar by directly screwing the set screw into the bus bar without using a nut.

In the battery pack of the present invention, the bus bar 5 has a through hole 5x through which the set screw 7 is inserted, and a nut into which the set screw 7 is screwed is arranged on the surface of the through hole 5x. The electrode tab 3 can be fixed to the bus bar 5 by passing through the bus bar 5 and screwed into the nut 17.
The battery pack described above can be electrically connected by inserting the set screw into the electrode tab and the bus bar and screwing it into the nut so that the electrode tab is securely stacked on the bus bar.

In the battery pack of the present invention, the electrode insulating separator 6 can be made of insulating plastic.
The above battery pack can realize excellent insulating characteristics with the electrode insulating separator while mass-producing the electrode insulating separator at a low cost.

The battery pack of the present invention includes a battery holder 2 that places the unit cell 1 in a fixed position, and the unit cell 1 that is connected to the battery holder 2 can be stacked to form a battery stack 9.
The battery pack described above has a feature that the battery stack can be assembled by arranging the unit cells in a fixed position with the battery holder.

In the battery pack of the present invention, the electrode insulating separator 6 includes a gap 6C in which the stepped bent portion 5C of the bus bar 5 is disposed, and the insulating rib 6D that insulates the bus bar 5 having a voltage difference is provided in the gap 6C. Can do.
The above battery pack can reduce heat conduction from the electrode tab and bus bar to the electrode insulating separator while easily setting the bus bar at a fixed position.

  In the battery pack of the present invention, the unit cell 1 can be a laminated battery. Further, in the battery pack of the present invention, the unit cell 1 can be either a lithium polymer battery or a lithium ion battery.

It is a disassembled perspective view of the conventional battery pack. It is a disassembled perspective view of the battery laminated body of the battery pack shown in FIG. It is a perspective view of the battery pack concerning one embodiment of the present invention. FIG. 4 is an exploded perspective view of the battery pack shown in FIG. 3. FIG. 4 is a vertical sectional view of the battery pack shown in FIG. 3. It is a perspective view of a unit cell. It is a perspective view of a battery holder. It is a bottom perspective view of the battery holder shown in FIG. It is a perspective view of a bus bar. It is an expanded sectional view which shows the connection structure of a set screw and a bus bar. It is an expanded sectional view which shows another example of the connection structure of a set screw and a bus-bar. It is the disassembled perspective view which looked at the electrode insulation separator adjacent up and down from the lower side. FIG. 6 is a cross-sectional view showing an assembly process of the battery pack shown in FIG. 5. FIG. 6 is a cross-sectional view showing an assembly process of the battery pack shown in FIG. 5. FIG. 6 is a cross-sectional view showing an assembly process of the battery pack shown in FIG. 5. FIG. 6 is a cross-sectional view showing an assembly process of the battery pack shown in FIG. 5. FIG. 6 is a cross-sectional view showing an assembly process of the battery pack shown in FIG. 5.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows. In addition, the member shown by the claim is not what specifies the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.

  The battery pack shown in FIGS. 3-5 is laminated | stacked on the battery laminated body 9 formed by laminating | stacking the several unit cell 1, and the battery laminated body 9, and has fixed the battery laminated body 9 in the laminated state. Between the base plate 4, the bus bar 5 connected to the electrode tab 3 of each unit cell 1 constituting the cell stack 9 and connecting the unit cell 1, and the electrode tab 3 of the stacked unit cell 1 And an electrode insulating separator 6 that insulates the electrode tab 3 from the bus bar 5 connected thereto.

(Battery laminate 9)
The battery stack 9 includes a plurality of unit cells 1, a battery holder 2 in which the unit cells 1 are disposed at fixed positions, and a cushion sheet 13 disposed between the bottom surface of the battery holder 2 and the unit cells 1. . In the illustrated battery stack 9, ten unit cells 1 are stacked. However, the battery stack does not specify the number of unit cells to be stacked, and can be, for example, 5 to 30, preferably 5 to 20. The unit cell 1 is a lithium polymer battery. However, the unit cell is not necessarily specified as a lithium polymer battery, and any other unit cell that can be charged, such as a lithium ion battery, can be used.

  In the battery stack 9, the positive electrode tabs 3A of each unit cell 1 are arranged in one row apart in the stacking direction of the unit cells 1, and the negative electrode tab 3B is also separated in the stacking direction in one row. The unit cells 1 are stacked so that the positive electrode tab 3A and the negative electrode tab 3B are arranged in two rows. The battery stack 9 is connected to each other in series by connecting the left and right electrode tabs 3 of the unit cells 1 stacked adjacent to each other with a bus bar 5.

(Unit cell 1)
The unit cell 1 is a flat battery having a rectangular outer shape as shown in the perspective view of FIG. The unit cell 1 in FIG. 6 is a laminate battery. However, the unit cell is not specified as a laminate battery, and all secondary batteries that can be stacked to form a battery stack, such as a metal outer can, are sealed with a sealing plate and filled with an electrode body and an electrolyte. You can also use a metal case secondary battery. A laminated battery has an aluminum film laminated with a plastic film or the like superimposed on an electrode body from above and below and welded at its end face. Each unit cell 1 has a rectangular outer shape, and has a positive electrode tab 3A on one side (left side in FIG. 6) and a negative electrode tab 3B on the other side (right side in FIG. 6). It is arranged. The electrode tab 3 is a thin metal plate, and protrudes from one side of the quadrilateral in a posture positioned in a plane parallel to the main surface 1A of both sides of the unit cell 1, that is, a plane parallel to the stack surface of the battery stack 9.

(Battery holder 2)
The battery holder 2 is formed by molding an insulating plastic, and is provided with a peripheral wall 22 around the bottom plate 21 that is a quadrangle so that the unit cell 1 is placed inside and placed in a fixed position. The battery holder 2 shown in the figure is provided with an electrode insulating separator 6 integrally formed. The battery holder 2 is provided with a peripheral wall 22 on three sides of a bottom plate 21 having a rectangular outer shape, and an electrode insulating separator 6 on one side. The battery holder 2 is stacked in a state where the unit cell 1 is disposed inside the peripheral wall 22. The battery stack 9 is stacked in multiple stages with the peripheral walls 22 of the stacked battery holders 2 in contact with each other. The battery holder 2 is laminated by adhering the unit cell 1 placed inside the peripheral wall 22 to the bottom plate 21 via an adhesive tape 14 such as a double-sided adhesive tape.

  The battery holder 2 of FIGS. 7 and 8 is provided with a protrusion 23 on the outer side of the peripheral wall 22, and a connection hole 24 through which the connection screw 15 </ b> A as the connection tool 15 is inserted. The connector 15 connects the battery holder 2 and the base plate 4 stacked on each other. A predetermined number of battery holders 2 in which the unit cells 1 are placed are stacked on the base plate 4 to form a battery stack 9. Further, the battery stack 9 is fixed to the base plate 4 via a connection screw 15 </ b> A inserted through the connection hole 24 of the battery holder 2.

  As shown in the figure, the electrode insulating separator 6 formed integrally with the battery holder 2 is disposed at a fixed position via the battery holder 2. However, the battery holder does not necessarily need to integrally form the electrode insulating separator. The electrode insulating separator that is not integrally molded with the battery holder is molded of plastic as a separate part separated from the battery holder. This electrode insulation separator, that is, an electrode insulation separator that is not connected to the battery holder, is disposed at a fixed position via a set screw 7 that fixes an electrode tab 3 to be described later to the bus bar 5, and a fixture is fixed to the outer surface. And placed in place.

(Base plate 4)
3-5, the battery laminated body 9 has arrange | positioned the baseplate 4 on the upper surface, connects the battery laminated body 9 to the baseplate 4 with the connector 15, and has fixed the unit cell 1 in the lamination | stacking state. . The base plate 4 has a plate shape and is approximately the same size as this so that the main surface 1A of the unit cell 1 can be completely covered. The base plate 4 is preferably made of plastic having excellent insulating properties. However, if insulation can be ensured, it may be metallic with higher strength.

(Connector 15)
The base plate 4 disposed on one surface of the battery stack 9 is fixed by a connector 15. The connecting tool 15 shown in the figure is a connecting screw 15A. As shown in FIG. 4, the connecting tool 15 of the connecting screw 15A is inserted into a connecting hole 24 of a protruding portion 23 provided to protrude outside the peripheral wall 22 of the battery holder 2, and a nut 15B is screwed into the tip thereof to attach the base plate 4 to the connecting screw 15A. Fix it.

(Bus bar 5)
The bus bar 5 is connected to the electrode tab 3 of the unit cell 1 constituting the battery stack 9 and connects the adjacent unit cells 1 in series. As shown in FIG. 9, the bus bar 5 is provided with a step bent portion 5 </ b> C in the middle so that both end portions can be connected to the positive and negative electrode tabs 3 of the adjacent unit cell 1. Further, the bus bar 5 has a positive electrode connecting portion 5A connected to the positive electrode tab 3A of the unit cell 1 at one end of the step bent portion 5C and a negative electrode of the unit cell 1 at the other end. A negative electrode connection portion 5B is provided to connect to the electrode tab 3B. The positive electrode connecting portion 5A and the negative electrode connecting portion 5B are located in planes parallel to each other. The bus bar 5 has the positive electrode connecting portion 5A connected to the positive electrode tab 3A of the unit cell 1 and the negative electrode connecting portion 5B connected to the negative electrode tab 3B of the unit cell 1 so as to be stacked adjacent to each other. Are connected in series.

  The bus bar 5 is electrically connected by laminating the electrode tabs 3 and fixing the electrode tabs 3 with set screws 7 penetrating the electrode tabs 3. As shown in the enlarged sectional view of FIG. 10, the set screw 7 passes through the through hole 3 x of the electrode tab 3 and is screwed into the female screw hole 16 which is the through hole 5 x of the bus bar 5. Secure to. The bus bar 5 is provided with a plurality of through holes 5x in the positive connection portion 5A and the negative connection portion 5B, respectively. The bus bar 5 of FIG. 9 is provided with four through holes 5x in the positive connection portion 5A and the negative connection portion 5B. Since the electrode tab 3 is fixed to the bus bar 5 with a set screw 7 inserted into the through hole 5x of the bus bar 5, the electrode tab 3 of the unit cell 1 is also provided with a plurality of through holes 3x. The unit cell 1 of FIG. 6 is provided with four through holes 3x in each electrode tab 3. The set screw 7 is inserted into the through hole 3 x of the electrode tab 3 and the through hole 5 x of the bus bar 5 to fix the electrode tab 3 to the bus bar 5. The bus bar 5 having the through hole 5x as the female screw hole 16 is screwed with a set screw 7 to fix the electrode tab 3. In the battery pack of FIG. 5, set screws 7 formed by fixing the electrode tabs 3 of the unit cells 1 stacked adjacent to each other vertically to the bus bar 5 are alternately positioned in a direction parallel to the layered surface of the unit cells 1. Displaced. That is, two appropriate locations are selected from the connecting portion of the bus bar 5 facing each other and the four through holes 5x and 3x of the electrode tab 3, and the electrode tab 3 and the bus bar 5 are connected to each other via the set screw 7 at the two locations. It is connected. Furthermore, the set screws 7 that connect the electrode tabs 3 and the bus bars 5 facing each other in the adjacent unit cells 1 are arranged so as not to face each other in the stacking direction of the unit cells 1. That is, in the figure, the position of the set screw 7 that connects the electrode tab 3 of the unit cell 1 arranged in the upper stage and the bus bar 5 and the electrode tab 3 of the unit cell 1 arranged in the lower stage and the bus bar 5 are connected. The position of the set screw 7 is shifted in the horizontal direction so as not to face each other. Therefore, in the battery pack, as shown in FIG. 5, a plurality of set screws 7 arranged in the vertical direction are arranged in a staggered manner, and the electrode tab 3 is fixed to the bus bar 5. This fixing structure does not have the set screw 7 for fixing the electrode tab 3 of the upper unit cell 1 on the set screw 7, and can prevent the set screw 7 having a voltage difference from approaching. For this reason, even if the lamination | stacking space | interval of the unit cell 1 is narrowed, the set screw 7 with a voltage difference can be insulated in an ideal state.

  The above bus bar 5 is provided with a female screw hole 16 on the inner surface of the through hole 5x. The bus bar 5 can fix the electrode tab 3 by screwing a set screw 7 into the female screw hole 16. This fixing structure can easily fix the set screw 7 to the bus bar 5 without using a nut. Further, this through hole allows the burr to protrude from the surface of the bus bar, and a female screw is also provided on the inner surface of the burr so that the set screw can be more securely fixed. However, the through hole of the bus bar is not necessarily a female screw hole. As shown in FIG. 11, the bus bar 5 has a nut 17 into which a set screw 7 is screwed on the surface of the through hole 5 x, and the nut 17 is screwed with the tip of the set screw 7 passing through the electrode tab 3 and the bus bar 5, The electrode tab 3 can also be fixed to the bus bar 5. The nut 17 can be disposed in a storage portion 6b formed in the electrode insulating separator 6 described later. In the above battery pack, the electrode tab 3 is fixed to the bus bar 5 with the set screw 7, but the electrode tab can also be fixed to the bus bar by welding. This fixing structure electrically connects the electrode tab to the bus bar without using a set screw.

(Electrode insulating separator 6)
The electrode insulating separator 6 is disposed between the bus bars 5 respectively connected to the opposing electrode tabs 3 of the stacked unit cells 1 to insulate the adjacent electrode tabs 3 from each other, and further to the bus bar having a voltage difference. Insulate 5 from each other. Since the electrode insulating separator 6 insulates the adjacent electrode tab 3 and the bus bar 5, it is formed of an insulating plastic. As shown in FIGS. 7 and 8, the electrode insulating separator 6 is a pair of insulating block portions disposed between the electrode tabs 3 of the unit cells 1 stacked one above the other and between the opposing bus bars 5. 6A is connected by a connecting part 6B on the battery side. The pair of insulating block portions 6A are separated from each other by a connecting portion 6B so that the stepped bent portion 5C of the bus bar 5 can be guided therebetween, and a gap 6C is provided between the insulating block portions 6A. In this gap 6 </ b> C, insulating ribs 6 </ b> D that are inserted between the upper and lower bus bars 5 and insulate the bus bars 5 are arranged. The insulating rib 6D is connected to the connecting portion 6B on the battery side. The insulating rib 6D is connected to the connecting portion 6B in a posture inclined at an angle equal to the inclination of the step bent portion 5C of the bus bar 5.

  The electrode insulating separator 6 is disposed between the bus bars 5 having a voltage difference, but is not connected to both the bus bar 5 and the electrode tab 3. Furthermore, the battery pack of FIG. 5 does not connect the electrode insulating separator 6 to the set screw 7 as shown in the enlarged cross-sectional view of the main part of FIG. Since the set screw 7 is fixed to the electrode tab 3 and the bus bar 5, when the electrode insulating separator 6 is connected to the set screw 7, the heat generated in the electrode tab 3 is thermally conducted to the electrode insulating separator 6 through the set screw 7. This is because that.

  As shown in the sectional views of FIGS. 5 and 10, the electrode insulating separator 6 is disposed between the bus bars 5 connected to the electrode tabs 3 facing each other in the adjacent unit cell 1. The screw 7 protrudes. Therefore, the electrode insulating separator 6 is provided with storage portions 6 a and 6 b that guide the portions where the set screw 7 protrudes from the surfaces of the electrode tab 3 and the bus bar 5. The storage portions 6a and 6b can be through holes or recesses that can guide the portion from which the set screw 7 protrudes. In the electrode insulating separator 6 of FIGS. 5 and 10, the storage portion 6 a that guides the head of the set screw 7 is a through hole, and the storage portion 6 b that guides the tip of the set screw 7 is a recess. The electrode insulating separator 6 having a housing portion 6 a that guides the head of the set screw 7 as a through hole can be fixed by inserting a screwdriver into the through hole and screwing the set screw 7 into the bus bar 5.

  In the illustrated electrode insulating separator 6, four insulating portions 6 a and 6 b are provided in each insulating block portion 6 </ b> A. The four storage portions 6a and 6b are provided at positions facing the four through holes 3x of the electrode tabs 3 of the stacked unit cells 1, respectively. Further, the electrode insulating separator 6 is provided with two storage portions 6a and two storage portions 6b alternately in each insulating block portion 6A. Here, as shown in FIG. 12, the electrode insulating separators 6 that are vertically adjacent to each other have a storage portion 6a that guides the head portion of the set screw 7 and a storage portion 6b that guides the tip end portion of the set screw 7. Four storage portions 6a and 6b are provided so as to be in opposite positions. As described above, the set screws 7 for fixing the electrode tabs 3 of the unit cells 1 stacked adjacent to each other vertically to the bus bar 5 are alternately displaced so as not to face each other in the stacking direction of the unit cells 1. It is for arranging. Accordingly, the electrode insulating separator 6 disposed adjacent to the upper and lower sides is provided with two types of first electrode insulating separator 6M and second electrode insulating separator provided so that the positions of the storage portions 6a and 6b are opposite to each other. 6N are alternately laminated. As shown in FIG. 12, the first electrode insulating separator 6M and the second electrode insulating separator 6N that are adjacent to each other are provided so that the one storage portion 6a faces the other storage portion 6b. That is, in the electrode insulating separators 6 adjacent to each other, the storage portion 6a of the first electrode insulating separator 6M and the storage portion 6b of the second electrode insulating separator 6N face each other, and the storage portion 6b of the first electrode insulating separator 6M The accommodating portion 6a of the second electrode insulating separator 6N is opposed to the second electrode insulating separator 6N. The electrode insulating separators 6 stacked in multiple stages are formed by alternately stacking the first electrode insulating separator 6M and the second electrode insulating separator 6N in which the positions of the storage portions 6a and 6b are opposite to each other. As shown in FIG. 2, a plurality of set screws 7 arranged vertically are arranged in a staggered manner.

  The electrode insulating separator 6 formed integrally with the battery holder 2 is disposed at a predetermined position via the battery holder 2. The electrode insulating separator that is not integrally formed with the battery holder is disposed at a fixed position by guiding a set screw to the storage portion. Further, the electrode insulating separator 6 shown in FIGS. 3 and 4 is connected to the fixed position by the connecting bar 10 by fixing the connecting bar 10 extending in the stacking direction.

  The above battery pack is assembled as follows. The battery pack of FIGS. 3 to 5 has the circuit board 8 mounted on the upper surface. However, as shown in FIGS. 13 to 17, the battery pack is inverted upside down, that is, the base plate 4 for fixing the circuit board 8 is assembled. It is assembled by placing it below.

(1) The unit cell 1 is disposed inside the peripheral wall 22 of the battery holder 2, and the unit cell 1 is bonded to the bottom plate 21 of the battery holder 2 via the adhesive tape 14 that is a double-sided adhesive tape. In this way, a predetermined number of battery holders 2 in which the unit cells 1 are arranged at a fixed position are prepared.

(2) In use, the base plate 4 disposed on the upper surface is turned upside down and placed on the horizontal table 50 as shown in FIG. Furthermore, after placing an output terminal plate 11 serving as an output terminal on the base plate 4, a battery holder 2 to which the unit cell 1 is bonded is laminated on the base plate 4 via a cushion sheet 13.
In this state, the positive electrode tab 3 </ b> A which is one (right side in the figure) of the unit cell 1 is fixed to the output terminal plate 11 with the set screw 7.

(3) Next, as shown in FIG. 14, the bus bar 5 is disposed at a fixed position of the electrode insulating separator 6 laminated on the base plate 4. The bus bar 5 has an insulating block portion 6A (in the drawing, in which the positive electrode connection portion 5A is laminated on the upper surface of the insulating block portion 6A (on the right side in the drawing) where the positive electrode tab 3A is arranged, and the negative electrode tab 3B is arranged. On the lower surface side of the left side), the negative electrode connection portion 5B is laminated, and the stepped bent portion 5C is disposed in the gap 6C between the pair of insulating block portions 6A. The negative connection portion 5B of the bus bar 5 is inserted into a gap formed between the negative electrode tab 3A and the base plate 4 disposed on the lower surface of the insulating block portion 6A, and is disposed at a fixed position. Further, the step bent portion 5C of the bus bar 5 is disposed on the upper surface side of the insulating rib 6D disposed in the gap 6C. The bus bar 5 is inserted into the electrode insulating separator 6 from the side surface direction (direction perpendicular to the paper surface in FIG. 14).
In this state, the negative electrode tab 3B which is the other electrode tab 3 of the unit cell 1 (left side in the figure) is fixed to the negative electrode connection portion 5B of the bus bar 5 with the set screw 7.

(4) Further, as shown in FIG. 15, the second-stage battery holder 2 to which the unit cells 1 are bonded is stacked on the lowermost-stage battery holder 2 via the cushion sheet 13. At this time, the second-stage electrode insulating separator 6 is disposed at a position facing the pair of insulating block parts 6A of the electrode insulating separator 6 in which the pair of insulating block parts 6A are stacked in the lower stage.
In this state, the positive electrode tab 3 </ b> A which is one (right side in the drawing) of the unit cell 1 is fixed to the positive connection portion 5 </ b> A of the bus bar 5 with the set screw 7. The set screw 7 is fixed while being displaced in the horizontal direction with respect to the set screw 7 arranged at the lower stage.

(5) Further, as shown in FIG. 16, the bus bar 5 is disposed at a fixed position of the second-stage electrode insulating separator 6. The bus bar 5 has an insulating block portion 6A (in the drawing, in which the positive electrode connection portion 5A is laminated on the upper surface of the insulating block portion 6A (on the right side in the drawing) where the positive electrode tab 3A is arranged, and the negative electrode tab 3B is arranged. On the lower surface side of the left side), the negative electrode connection portion 5B is laminated, and the stepped bent portion 5C is disposed in the gap 6C between the pair of insulating block portions 6A. The negative electrode connecting portion 5B of the bus bar 5 is inserted into a gap formed between the negative electrode tab 3A disposed on the lower surface of the insulating block portion 6A and the lower insulating block portion 6A and disposed at a fixed position. Further, the step bent portion 5C of the bus bar 5 is disposed on the upper surface side of the insulating rib 6D disposed in the gap 6C. The bus bar 5 is inserted into the electrode insulating separator 6 from the side surface direction (direction perpendicular to the paper surface in FIG. 16).
In this state, the negative electrode tab 3B which is the other electrode tab 3 of the unit cell 1 (left side in the figure) is fixed to the negative electrode connection portion 5B of the bus bar 5 with the set screw 7. The set screw 7 is fixed while being displaced in the horizontal direction with respect to the set screw 7 arranged at the lower stage.

(6) Similarly, the steps (4) and (5) are repeated to form a battery stack 9 by stacking a predetermined number of battery holders 2, and the positive and negative of the unit cells 1 stacked on each other. The electrode tabs 3 are connected in series via the bus bar 5.

(7) As shown in FIG. 17, the positive electrode tab 3A, which is the electrode tab 3 on one side (right side in the figure) of the unit cells 1 stacked at the top, is connected to the positive connection portion 5A of the bus bar 5 with a set screw 7 The negative electrode tab 3B, which is the other electrode tab 3 (left side in the figure) of the unit cell 1, is fixed to the output terminal plate 12 with a set screw 7. The output terminal plate 12 shown in the figure is bent in an inverted L shape, and the connecting portion 12A is formed between the negative electrode tab 3A disposed on the lower surface of the insulating block portion 6A and the lower insulating block portion 6A. It is inserted into the gap and placed at a fixed position. The output terminal plate 12 has a connection portion 12A connected to the electrode tab 3 of the unit cell, and a distal end portion of an extension portion extended from the connection portion is coupled to the base plate 4 via a set screw 7.

(8) As described above, a predetermined number of battery holders 2 are stacked, and a battery stack 9 in which a predetermined number of unit cells 1 are stacked is connected to the base plate 4 via a connector 18 and turned upside down. In this state, the battery pack shown in FIG. 5 is obtained.

  The battery pack according to the present invention can be suitably used as a relatively large power supply device for electric motorcycles, electric vehicles, assist bicycles, and the like.

DESCRIPTION OF SYMBOLS 1 ... Unit cell 1A ... Main surface 2 ... Battery holder 3 ... Electrode tab 3A ... Electrode tab of positive electrode
3B ... Negative electrode tab
3x ... through hole 4 ... base plate 5 ... bus bar 5A ... positive electrode connection
5B ... Negative electrode connection
5C ... Step bending part
5x ... through hole 6 ... electrode insulating separator 6M ... first electrode insulating separator
6N ... second electrode insulation separator
6A ... Insulation block
6B ... Connection part
6C ... Gap
6D ... Insulating rib
6a ... Storage part
6b ... Storage part 7 ... Set screw 8 ... Circuit board 9 ... Battery stack 10 ... Connection bar 11 ... Output terminal board 12 ... Output terminal board 12A ... Connection part
12B ... Extension part 13 ... Cushion sheet 14 ... Adhesive tape 15 ... Connector 15A ... Connection screw
15B ... Nut 16 ... Female screw hole 17 ... Nut 21 ... Bottom plate 22 ... Surrounding wall 23 ... Protrusion 24 ... Connecting hole 50 ... Horizontal base 201 ... Unit cell 203 ... Electrode tab 203A ... Folded piece 204 ... End plate 205 ... Bus bar 206 ... Insulating holder 207 ... Set screw 208 ... Nut 209 ... Battery stack

Claims (11)

A battery laminate (9) formed by laminating a plurality of plate-like unit cells (1) each having a positive electrode tab (3A) and a negative electrode tab (3B);
A bus bar (5) connected to the electrode tab (3) of the unit cell (1) constituting the cell stack (9) and connected to the unit cell (1);
An electrode insulation separator (6) disposed between the bus bars (5) connected to the opposing electrode tabs (3) of the stacked unit cells (1) to insulate the bus bars (5) having a voltage difference from each other. A battery pack comprising:
The battery pack, wherein the electrode insulating separator (6) is disposed in a non-connected state with the bus bar (5) and the electrode tab (3). In the unit cell (1), the opposing main surface (1A) is planar and the outer shape is rectangular, and a positive electrode tab (3A) and a negative electrode tab (3B) are arranged on one side of the square. In addition, the positive and negative electrode tabs (3) are located in a plane parallel to the laminated surface and protrude from the outer periphery,
The positive electrode tabs (3A) of each unit cell (1) are separated in the stacking direction of the unit cells (1) and arranged in one row, and the negative electrode tab (3B) is also separated in the stacking direction. The positive electrode tab (3A) and the negative electrode tab (3B) are arranged in two rows,
The bus bar (5) has a step bent portion (5C) in the middle so that both ends are connected to the positive and negative electrode tabs (3) of the adjacent unit cell (1), and the step bent portion (5C ) At one end of the unit cell (1) is connected to the positive electrode tab (3A) of the unit cell (1), and at the other end of the unit cell (1). Provided with a negative electrode connection (5B) connected to the negative electrode tab (3B),
The positive connection (5A) is connected to the positive electrode tab (3A) of the unit cell (1), and the negative connection (5B) is connected to the negative electrode tab (3B) of the unit cell (1). (5) The battery pack according to claim 1, wherein the unit cells (1) stacked adjacent to each other are connected in series. A plurality of through holes (3x; 5x) are provided in the electrode tab (3) of the unit cell (1), and the positive electrode connection portion (5A) and the negative electrode connection portion (5B) of the bus bar (5), respectively. The electrode tab (3) is fixed to the bus bar (5) with a set screw (7) inserted into the through hole (3x) of the electrode tab (3) and the through hole (5x) of the bus bar (5). Are electrically connected,
Further, a set screw (7) formed by fixing the electrode tab (3) of the adjacent unit cell (1) to the bus bar (5) is positioned in a direction parallel to the layer surface of the unit cell (1). The battery pack according to claim 2, wherein the battery pack is arranged out of alignment.   The battery pack according to claim 3, wherein the electrode insulating separator (6) has a storage portion (6a; 6b) including a through hole or a recess for guiding the set screw (7).   The bus bar (5) has a female screw hole (16) for screwing and fixing the set screw (7), and the set screw (7) is screwed into the female screw hole (16) to form an electrode tab (3 The battery pack according to claim 3 or 4, wherein the battery pack is fixed to the bus bar (5).   The bus bar (5) has a through hole (5x) through which the set screw (7) is inserted, and a nut (17) into which the set screw (7) is screwed is disposed on the surface of the through hole (5x). A set screw (7) passes through the electrode tab (3) and the bus bar (5) and is screwed into the nut (17) to fix the electrode tab (3) to the bus bar (5). The battery pack described in 3 or 4.   The battery pack according to any one of claims 1 to 6, wherein the electrode insulating separator (6) is an insulating plastic.   A battery stack (9) is formed by stacking unit cells (1) connected to the battery holder (2), comprising a battery holder (2) for arranging the unit cells (1) in place. The battery pack described in any one of 7 thru | or 7.   The electrode insulation separator (6) is provided with a gap (6C) for arranging the step bent portion (5C) of the bus bar (5), and the bus bar (5) having a voltage difference is provided in the gap (6C). The battery pack according to any one of claims 1 to 8, further comprising insulating ribs (6D) for insulation.   The battery pack according to any one of claims 1 to 9, wherein the unit cell (1) is a laminated battery.   The battery pack according to any one of claims 1 to 10, wherein the unit cell (1) is either a lithium polymer battery or a lithium ion battery.

Images