JP2021150131A - Power storage device - Google Patents

Abstract

To provide a power storage device that is able to improve the ability to fit a power storage unit and a shunt resistor together.SOLUTION: In a power storage device 10, a negative electrode connection tab 16 protrudes from a first side surface 11c of a power storage unit 11 along an extending direction X, and one electrode terminal 83 of a shunt resistor 81 is electrically connected to a negative electrode connection tab 16. In the power storage device 10, the circuit board is adjacent to the side surface 11c of the storage unit 11 such that the main surface of the board intersects the extending direction X. The negative electrode connection tab 16 has flat tab surfaces 16a on both surfaces thereof in a stacking direction, and the pair of electrode terminals 83 has flat main surfaces 83c on both surfaces thereof in a thickness direction. In the power storage device 10, one tab surface 16a of the negative electrode connection tab 16 and one main surface 83c of the one electrode terminal 83 are connected in contact with each other, one along the other.SELECTED DRAWING: Figure 1

Description

The present invention includes a power storage unit including a power storage module having a plurality of bipolar electrodes, a current collector having a connection tab, and a shunt resistor electrically connected to the connection tab, and a circuit board. Regarding the power storage device to have.

Conventionally, various power storage devices formed by stacking a plurality of bipolar electrodes have been proposed. For example, the power storage pack of Patent Document 1 has a power storage unit having a plurality of stacked bipolar electrodes, a positive electrode current collector plate, a negative electrode current collector plate, a positive electrode terminal, and a negative electrode terminal. The power storage unit has a substantially rectangular parallelepiped shape. The power storage unit is configured by stacking a plurality of power storage modules and a plurality of cooling plates. The positive electrode current collector plate is arranged on the lower end surface of the power storage unit. The positive electrode terminal is connected to the positive electrode current collector plate. The negative electrode current collector plate is arranged on the upper end surface of the power storage unit. The negative electrode terminal is connected to the negative electrode current collector plate.

The positive electrode terminal is connected to the side portion of the positive electrode current collector plate facing the short side surface of one of the side surfaces of the power storage unit. The positive electrode terminal extends upward from the side portion of the positive electrode current collector plate and is bent so as to be separated from the short side surface of the power storage unit in the vicinity of the negative electrode current collector plate. When the power storage unit is viewed from the upper end surface, the tip of the positive electrode terminal has a rectangular shape.

The negative electrode terminal is connected to the side portion of the negative electrode current collector plate facing the short side surface of one of the side surfaces of the power storage unit. The short side surface to which the negative electrode terminal is connected is the same as the short side surface to which the positive electrode terminal is connected. The negative electrode terminal protrudes from the side portion of the negative electrode current collector so as to be separated from the short side surface of the power storage unit. When the power storage unit is viewed from the upper end surface, the tip of the negative electrode terminal has a rectangular shape.

Further, in a device provided with a power storage device and a load for driving the power storage device as a power source, the power storage device is used for the purpose of determining whether or not an overcurrent has occurred and estimating the charge rate of the power storage device. The current is being measured. Some current measuring devices include a shunt resistor and a circuit board including a measuring unit for measuring the voltage of a pair of electrode terminals sandwiching the resistor of the shunt resistor. For example, the battery control device of Patent Document 2 has a shunt resistor and a battery control board as a circuit board including a current detection unit as a measurement unit, and a part of the shunt resistor is on the battery control board. Is located in.

Japanese Unexamined Patent Publication No. 2019-197670 Japanese Patent No. 6430218

The inventor has considered to install a current measuring device as in Patent Document 2 in a power storage unit having a plurality of bipolar electrodes to measure the current flowing through the power storage unit. In this case, one electrode terminal of the shunt resistor and, for example, the negative electrode terminal of the power storage unit are electrically connected, but the circuit board is arranged so that the main surface of the circuit board is along the short side surface of the power storage unit. Will be done. Therefore, the main surface of one electrode terminal of the shunt resistor is arranged so as to be orthogonal to the main surface of the negative electrode terminal. Therefore, in order to electrically connect between one of the electrode terminals and the negative electrode terminal while suppressing the electrical resistance, for conductivity having a portion in which the main surface of the electrode terminal and the main surface of the negative electrode terminal are in surface contact with each other. There is a problem that the assembling property between the power storage unit and the shunt resistor is not good because a separate member is required.

An object of the present invention is to provide a power storage device capable of improving the assembling property of a power storage unit and a shunt resistor.

In the power storage device for solving the above problems, a power storage module having a plurality of stacked bipolar electrodes and a current collector main body are laminated in the stacking direction of the bipolar electrodes in the power storage module, and the current collector is laminated. It has a power storage unit including a current collector having a connection tab protruding from the current collector main body in an extension direction intersecting the stacking direction of the main body, and also has a resistor and a pair of electrode terminals sandwiching the resistor. It has a shunt resistor that is arranged side by side in the parallel direction and is adjacent to the power storage unit in the extension direction, and a circuit board on which a measuring unit for measuring the voltage of the pair of electrode terminals is arranged. Among the surfaces of the power storage unit, the connection tab protrudes from the side surface intersecting both end surfaces in the stacking direction along the extension direction, and one of the pair of electrode terminals is electrically connected to the connection tab. A power storage device that is connected and adjacent to the power storage unit in a state where the main surfaces of the circuit board intersect in the extension direction, and the connection tab has flat tab surfaces on both sides in the stacking direction. The pair of electrode terminals have flat main surfaces on both sides in the thickness direction, and one of the tab surfaces of the connection tab and one of the main surfaces of the electrode terminals are aligned with each other. The gist is that they are connected in surface contact with the state.

According to this, in a configuration in which the power storage unit and the shunt resistor are adjacent to each other in the extension direction and the main surface of the circuit board intersects in the extension direction, the circuit board extends from the power storage unit along the extension direction. There is no release, and there is no increase in the size of the power storage device. In such a power storage device, the connection tab and the electrode terminal are arranged so that the tab surface and the main surface are in surface contact with each other, and electricity is performed in a state where the electrical resistance between the connection tab and the electrode terminal is suppressed to a low level. Can be connected. For example, in a configuration in which the main surface of the connection tab is orthogonal to the main surface of the electrode terminal, both the tab surface and the main surface are in surface contact in order to reduce the electrical resistance between the connection tab and the electrode terminal. A separate member with a portion is required. However, by arranging the tab surface and the main surface in surface contact with each other, the tab surface and the main surface can be electrically connected without the need for a separate member, and the electrode terminals can be compared with the case where a separate member is used. The ease of assembly with the connection tab can be improved, and the ease of assembly between the power storage unit and the shunt resistor can be improved.

Regarding the power storage device, the shunt resistor and the circuit board are electrically connected via a connecting member, and the connecting member is a flat plate-shaped resistor-side connecting portion fixed to the shunt resistor and the circuit board. The shunt resistor and the circuit board are viewed from one end side in the juxtaposed direction by having a flat plate-shaped substrate-side connection portion fixed to the above and intersecting the resistance-side connection portion and the substrate-side connection portion. From the side view, the connecting member may have an L shape.

According to this, in a state where the main surface of the electrode terminal and the tab surface of the connection tab are in surface contact with each other along each other, the substrate main surface of the circuit board is crossed in the extending direction of the connection tab by the connection member. The circuit board can be placed in the state.

Regarding the power storage device, the substrate-side connection portion may have a plurality of fixed position adjusting portions arranged in a direction protruding from the resistance-side connection portion.
According to this, while the circuit board is mounted at a predetermined mounting position with respect to the power storage unit, when the number of power storage modules in the power storage unit is changed, the position of the current collector along the stacking direction changes. .. At this time, by adjusting the fixed position of the connecting member with respect to the circuit board by the fixed position adjusting unit, the position of the electrode terminal of the shunt resistor can be adjusted in accordance with the position change of the current collector. As a result, it becomes easy to align the main surface of the electrode terminal with the tab surface of the current collector.

According to the present invention, the assembling property between the power storage unit and the shunt resistor can be improved.

The perspective view which shows the power storage device. An exploded perspective view showing a current measuring device. FIG. 2 is a cross-sectional view showing the internal structure of the power storage module. Partial perspective view showing a shunt resistor, a circuit board, and a connecting member. A partial perspective view showing a shunt resistor in a current measuring device. A cross-sectional view showing a current measuring device. The cross-sectional view which shows the current measuring apparatus after height adjustment.

Hereinafter, an embodiment in which the power storage device is embodied will be described with reference to FIGS. 1 to 7.
The power storage device is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles.

As shown in FIG. 1, the power storage device 10 includes a power storage unit 11, a restraint member 21, and a current measuring device 50. The power storage unit 11 includes a plurality of long square flat plate-shaped power storage modules 12, a plurality of long square flat plate-shaped conductive plates 13, and a long square flat plate-shaped negative electrode current collector electrically connected to the plurality of long square flat plate-shaped conductive plates 13. 14 and a long square flat plate-shaped positive electrode current collector 17 are laminated in the plate thickness direction. In the power storage unit 11, the direction in which the plurality of power storage modules 12, the conductive plate 13, the negative electrode current collector 14 and the positive electrode current collector 17 are laminated is defined as the stacking direction D.

The power storage unit 11 has a substantially rectangular parallelepiped shape. Of the six side surfaces of the power storage unit 11, the first end surface in the stacking direction D is the upper end surface 11a, and the second end surface in the stacking direction D is the lower end surface 11b. Of the four side surfaces connecting the upper end surface 11a and the lower end surface 11b of the power storage unit 11, the side surfaces located at both ends in one direction of the upper end surface 11a are designated as the first side surface 11c, and the side surfaces orthogonal to one direction of the upper end surface 11a are orthogonal to each other. The side surfaces located at both ends are referred to as the second side surface 11d.

The plurality of power storage modules 12 are connected in series with each other. The power storage module 12 is a bipolar battery and has an elongated shape when viewed from the stacking direction D. The power storage module 12 is, for example, a secondary battery such as a nickel hydrogen secondary battery and a lithium ion secondary battery, or an electric double layer capacitor. Further, viewing the power storage unit 11 from the upper end surface 11a or the lower end surface 11b along the stacking direction D may be referred to as a plan view.

The conductive plate 13 is arranged between the two power storage modules 12 adjacent to each other in the stacking direction D. The two power storage modules 12 adjacent to each other in the stacking direction D are electrically connected to each other via the conductive plate 13. In a plan view, the conductive plate 13 is one size smaller than the power storage module 12. Therefore, the four side surfaces connecting the upper end surface 11a and the lower end surface 11b of the power storage unit 11 are formed by the surfaces connecting the side surfaces of the power storage module 12 exposed on each side surface in the stacking direction D. That is, the first side surface 11c and the second side surface 11d of the power storage unit 11 are composed of surfaces that connect the side surfaces of the power storage module 12 exposed on each side surface in the stacking direction D.

The negative electrode current collector 14 is arranged at the upper end of the stacking direction D of the power storage unit 11 and constitutes the upper end surface 11a of the power storage unit 11. The negative electrode current collector 14 is connected to a long square flat plate-shaped negative electrode current collector main body 15 as a current collector main body laminated on the power storage module 12 and protruding from one side of the negative electrode current collector main body 15. It has a negative electrode connection tab 16 as a tab and a negative electrode connection tab 16. In the plan view of the power storage unit 11, the negative electrode current collector main body 15 is an oblong metal plate having an area one size smaller than the area of the power storage module 12. The negative electrode connection tab 16 has flat tab surfaces 16a on both sides in the stacking direction D.

The negative electrode connection tab 16 projects from one of the first side surfaces 11c of the pair of first side surfaces 11c of the power storage unit 11. That is, the negative electrode connection tab 16 projects from the first side surface 11c of the surface of the power storage unit 11 that intersects both end surfaces in the stacking direction D along the extension direction X. The negative electrode connection tab 16 has a rectangular shape in a plan view. The negative electrode connection tab 16 projects from the negative electrode current collector main body 15 in the extension direction X intersecting the stacking direction D of the negative electrode current collector main body 15.

The positive electrode current collector 17 is arranged at the lower end of the stacking direction D of the power storage unit 11 and constitutes the lower end surface 11b of the power storage unit 11. The positive electrode current collector 17 is a long square flat plate-shaped positive electrode current collector main body 18 as a current collector main body laminated on the power storage module 12, and a connection tab protruding from one side of the positive electrode current collector main body 18. The positive electrode connection tab 19 and the like. In the plan view of the power storage unit 11, the positive electrode current collector main body 18 is an oblong metal plate having an area one size smaller than the area of the power storage module 12. The positive electrode connection tab 19 has rectangular tab surfaces 19a on both sides in the stacking direction D.

The positive electrode connection tab 19 projects from one of the first side surfaces 11c of the pair of first side surfaces 11c of the power storage unit 11. That is, the positive electrode connection tab 19 projects from the first side surface 11c of the surface of the power storage unit 11 that intersects both end surfaces in the stacking direction D along the extension direction X. The positive electrode connection tab 19 projects from the first side surface 11c from which the negative electrode connection tab 16 projects. The positive electrode connection tab 19 has a rectangular shape in a plan view. The positive electrode connection tab 19 projects from the positive electrode current collector main body 18 along the extension direction X intersecting the plate thickness direction of the positive electrode current collector main body 18.

The restraint member 21 is a member that applies a restraint load along the stacking direction D to the power storage unit 11. The restraint member 21 has a pair of end plates 22 that sandwich the power storage unit 11 in the stacking direction D, and a fastening bolt 23 and a nut 24 that fasten the pair of end plates 22 to each other. The end plate 22 is a metal plate having an area one size larger than the areas of the power storage module 12, the conductive plate 13, the negative electrode current collector 14, and the positive electrode current collector 17 in a plan view from the stacking direction D. An insulating plate 25 having electrical insulation is provided on the inner surface of the end plate 22. The insulating plate 25 insulates between one end plate 22 and the negative electrode current collector 14, and between the other end plate 22 and the positive electrode current collector 17.

An insertion hole (not shown) is provided at the edge of each end plate 22 at a position outside the power storage unit 11. The fastening bolt 23 is passed from the insertion hole of one end plate 22 toward the insertion hole of the other end plate 22, and a nut 24 is attached to the tip portion of the fastening bolt 23 protruding from the insertion hole of the other end plate 22. Is screwed. Instead of the nut 24, the other end plate 22 may be provided with a female threaded portion, and the fastening bolt 23 may be screwed into the female threaded portion. As a result, the power storage module 12, the conductive plate 13, the negative electrode current collector 14, and the positive electrode current collector 17 are sandwiched between the pair of end plates 22 to be unitized as the power storage unit 11, and are laminated on the power storage unit 11. A restraining load is applied in the direction D.

As shown in FIG. 3, each of the plurality of power storage modules 12 includes an electrode laminated body 31 and a sealing body 32 that seals the electrode laminated body 31. The electrode laminate 31 has a plurality of separators 33, a plurality of bipolar electrodes 34, a negative electrode terminal electrode 35, and a positive electrode terminal electrode 36. In the electrode laminate 31, the plurality of separators 33, the plurality of bipolar electrodes 34, the negative electrode terminal electrode 35, and the positive electrode terminal electrode 36 are each in the form of a sheet. The plurality of separators 33, the plurality of bipolar electrodes 34, the negative electrode terminal electrode 35, and the positive electrode terminal electrode 36 are laminated in the thickness direction, respectively. The direction in which the plurality of separators 33, the plurality of bipolar electrodes 34, the negative electrode terminal electrode 35, and the positive electrode terminal electrode 36 are laminated is defined as the stacking direction D1 of the electrode laminate 31. The stacking direction D1 of the electrode laminate 31 is the stacking direction of the bipolar electrodes 34 in the power storage module 12, and coincides with the stacking direction D of the power storage module 12, the conductive plate 13, the negative electrode current collector 14, and the positive electrode current collector 17.

The negative electrode terminal electrode 35, the plurality of bipolar electrodes 34, and the positive electrode terminal electrode 36 are laminated in this order from top to bottom along the stacking direction D1. Between two bipolar electrodes 34 adjacent to each other in the stacking direction D1, between the negative electrode termination electrodes 35 and the bipolar electrodes 34 adjacent to each other in the stacking direction D1, and between the positive electrode termination electrodes 36 and the bipolar electrodes adjacent to each other in the stacking direction D1. Separators 33 are arranged in each of the spaces between the 34 and the 34. Each of the plurality of bipolar electrodes 34 includes an electrode plate 34a, a positive electrode 34b, and a negative electrode 34c. The electrode plate 34a is a chemically inert electronic conductor for keeping current flowing through the bipolar electrode 34 during discharging or charging of the lithium ion secondary battery, for example copper, nickel, aluminum, stainless metal or It is made of a plate made of alloy and has a rectangular shape.

The positive electrode 34b is provided on one surface of the electrode plate 34a. The negative electrode 34c is provided on the other surface of the electrode plate 34a. In the present embodiment, in a plan view, the formation region of the negative electrode 34c on the other surface of the electrode plate 34a is one size larger than the formation region of the positive electrode 34b on one surface of the electrode plate 34a. The bipolar electrode 34 is formed by superimposing an electrode plate having a positive electrode 34b on one surface and an electrode plate having a negative electrode 34c on one surface, respectively, on surfaces not provided with a positive electrode 34b and a negative electrode 34c, respectively. It may be composed of the formed electrode plate 34a.

In the electrode laminate 31, the positive electrode 34b of one bipolar electrode 34 faces the negative electrode 34c of another bipolar electrode 34 adjacent to the stacking direction D1 with the separator 33 interposed therebetween. In the electrode laminate 31, the negative electrode 34c of one bipolar electrode 34 faces the positive electrode 34b of another bipolar electrode 34 adjacent to the stacking direction D1 with the separator 33 interposed therebetween.

The negative electrode terminal electrode 35 is arranged at one end of the electrode laminate 31 in the stacking direction D1. The negative electrode terminal electrode 35 includes an electrode plate 34a and a negative electrode 34c provided on one surface of the electrode plate 34a. The negative electrode 34c of the negative electrode terminal electrode 35 faces the positive electrode 34b of the bipolar electrode 34 adjacent to the stacking direction D1 via the separator 33. The other surface of the electrode plate 34a of the negative electrode terminal electrode 35 is in contact with the conductive plate 13 adjacent to the stacking direction D or the negative electrode current collector 14 constituting the upper end surface 11a.

The positive electrode terminal electrode 36 is arranged at the other end of the electrode laminate 31 in the stacking direction D1. The positive electrode terminal electrode 36 includes an electrode plate 34a and a positive electrode 34b provided on one surface of the electrode plate 34a. The positive electrode 34b of the positive electrode terminal electrode 36 faces the negative electrode 34c of the bipolar electrode 34 adjacent to the stacking direction D1 via the separator 33. The electrode plate 34a of the positive electrode terminal electrode 36 is in contact with the conductive plate 13 adjacent to the stacking direction D or the positive electrode current collector 17 constituting the lower end surface 11b.

The sealing body 32 is a sealing material that seals the separator 33 and the bipolar electrode 34, and is formed in, for example, a rectangular cylinder. The sealing body 32 is formed of an insulating resin material. The sealing body 32 is provided around the electrode laminated body 31, forms an internal space V in the electrode laminated body 31, and seals the internal space V. The internal space V contains an electrolytic solution (not shown) in which an electrolyte salt is dissolved in a solvent. The electrolytic solution is impregnated in the separator 33, the positive electrode 34b and the negative electrode 34c.

Next, the current measuring device 50 will be described in detail. The current measuring device 50 measures the current flowing in the current path from the power storage unit 11 to the load.
As shown in FIG. 1 or 2, the current measuring device 50 includes a shunt resistor 81 and a circuit board 71 that is electrically connected to the shunt resistor 81. Further, the current measuring device 50 has a case 61 for accommodating the circuit board 71, and an external base 51 attached to the end plate 22 and to which the case 61 is fixed.

The external base 51 has a long square flat plate shape. The external base 51 is separated from one first side surface 11c of the power storage unit 11 along the extension direction X. That is, the external base 51 is separated from the first side surface 11c of the power storage unit 11 along the projecting direction of the negative electrode connection tab 16 from the negative electrode current collector main body 15.

The outer base 51 is a resin plate-like member having a base main surface 51a on both sides in the plate thickness direction. The external base 51 is fixed to the pair of end plates 22 via a fixing member 52 such as a bolt. In the present embodiment, the base main surface 51a of the external base 51 is parallel to or substantially parallel to the first side surface 11c of the power storage unit 11. One base main surface 51a faces one first side surface 11c of the power storage unit 11, and the case 61 is fixed to the other base main surface 51a. The external base 51 has a tab insertion hole 51b that penetrates the external base 51 in the plate thickness direction. The negative electrode connection tab 16 of the negative electrode current collector 14 penetrates the tab insertion hole 51b and projects toward the case 61.

The case 61 has a bottomed box-shaped first case member 62 made of metal and a covered cylinder-shaped second case member 63 made of synthetic resin. The first case member 62 includes a square plate-shaped bottom plate 62a, a first peripheral wall 62b erected from the edge of the bottom plate 62a, a plurality of board mounting bosses 62c erected from the bottom plate 62a, and four corners of the first peripheral wall 62b. It has a through hole 62d located at. A female screw (not shown) is provided on the inner peripheral surface of the board mounting boss 62c. Inside the first case member 62, a first accommodating portion S1 defined by a bottom plate 62a and a first peripheral wall 62b is defined. The first case member 62 has a communication port 62e that opens at the upper part of the first peripheral wall 62b.

The second case member 63 that closes the opening of the first case member 62 opens toward the first case member 62. The second case member 63 has a plate-shaped lid plate 64 and a second peripheral wall 65 erected from the edge of the lid plate 64. The second peripheral wall 65 has a recess 66 recessed from the upper surface of the second peripheral wall 65. Inside the second case member 63, a second accommodating portion S2 defined by a lid plate 64 and a second peripheral wall 65 is defined.

The second case member 63 has a bottom plate portion 66a located at a point where the recess 66 is recessed from the outer surface of the second peripheral wall 65. Further, the second case member 63 has a pair of nut receiving portions 66c recessed from the outer surface of the bottom plate portion 66a. A nut 70 is fitted in each nut receiving portion 66c. The nut 70 is supported on the inner bottom surface of the nut receiving portion 66c.

The second case member 63 has a pair of rivet accommodating portions 66d penetrating the bottom plate portion 66a in the plate thickness direction. Each rivet accommodating portion 66d is formed by cutting out a part of the bottom plate portion 66a from the opening side end of the second case member 63. The pair of rivet accommodating portions 66d are located between the pair of nut receiving portions 66c. Each rivet accommodating portion 66d accommodates an end portion of a resistance rivet 95, which will be described later.

The circuit board 71 is attached to the first case member 62 by screwing the board mounting screw 27 that penetrates the circuit board 71, which will be described in detail later, into the board mounting boss 62c. Further, the case fixing screw 26 inserted into the through hole 62d of the first case member 62 is screwed into a female screw (not shown) of the second case member 63, so that the first case member 62 and the second case member 63 are assembled. It is attached. The case 61 is formed by integrally assembling the first case member 62 and the second case member 63, and as shown in FIG. 6, the first accommodating portion S1 of the first case member 62 and the second case The accommodation space S of the circuit board 71 is defined in combination with the second accommodation portion S2 of the member 63.

As shown in FIG. 4, the shunt resistor 81 has, for example, a resistor 82 made of a resistance alloy such as Cu—Mn—Ni and a pair of electrode terminals 83 made of a metal such as Cu. .. The resistor 82 has a rectangular flat plate shape. Each electrode terminal 83 has a rectangular flat plate shape. The shunt resistor 81 is configured by arranging one electrode terminal 83, a resistor 82, and the other electrode terminal 83 in a line along the length of the electrode terminal 83. The longitudinal direction of the electrode terminal 83 is the direction in which the longitudinal direction of the two side surfaces having the largest area extends from the six side surfaces of the electrode terminal 83, and the lateral direction of the electrode terminal 83 is the direction in which the two side surfaces having the largest area extend. This is the direction in which the short side extends.

In the shunt resistor 81, the direction in which one electrode terminal 83, the resistor 82, and the other electrode terminal 83 are lined up in a row is defined as the parallel arrangement direction F. Further, the parallel direction F of the shunt resistor 81 coincides with the longitudinal direction of the electrode terminal 83. Further, the direction connecting the two side surfaces having the largest area of the electrode terminal 83 is defined as the thickness direction R of the shunt resistor 81. The parallel direction F is one direction that intersects the thickness direction R of the shunt resistor 81.

Each electrode terminal 83 has a main surface 83c on both sides in the thickness direction R, and each main surface 83c has a rectangular shape in a plan view. The two main surfaces 83c are the two surfaces having the largest area among the six surfaces of the electrode terminal 83.

Each electrode terminal 83 has a through hole 83a near the resistor 82 in the parallel direction F. The through hole 83a penetrates the electrode terminal 83 in the thickness direction R. Further, each electrode terminal 83 has a connecting hole 83b near the end on the side opposite to the through hole 83a in the parallel direction F. The connecting hole 83b penetrates the electrode terminal 83 in the thickness direction R.

As shown in FIG. 4 or 6, the circuit board 71 has a substrate main surface 71a on both sides in the plate thickness direction D2. A voltage amplification IC 72 as a measuring unit is arranged on one of the main surfaces 71a of the substrate. The voltage amplification IC 72 is mounted on the main surface 71a of the substrate by soldering. The voltage amplification IC 72 is an integrated circuit for converting the current flowing in the current path from the power storage unit 11 to the load into a measurable voltage. Holes 71b are provided at the four corners of the circuit board 71. The above-mentioned board mounting screw 27 is inserted into each hole 71b.

The circuit board 71 and the shunt resistor 81 are integrated by two connecting members 91. That is, a pair of connecting members 91 are connected to the shunt resistor 81 and the circuit board 71. When the shunt resistor 81 and the circuit board 71 are viewed from one end side in the parallel direction F, the connecting member 91 has an L shape. Therefore, each connecting member 91 is made of an L-shaped conductive material. In this embodiment, the connecting member 91 is made of copper. Each connecting member 91 has a flat plate-shaped resistance side connecting portion 93 fixed to the shunt resistor 81 and a flat plate-shaped substrate side connecting portion 92 fixed to the circuit board 71.

The board-side connection portion 92 is fastened to a wiring pattern (not shown) of the circuit board 71, and the resistance-side connection portion 93 is fastened to the electrode terminal 83 of the shunt resistor 81. Of the five side surfaces of the substrate-side connecting portion 92, one of the two surfaces having the largest area is the outer surface 92a, and the other is the inner surface 92b. Further, of the five side surfaces of the resistance side connecting portion 93, one of the two surfaces having the largest area is designated as the outer surface 93a, and the other is designated as the inner surface 93b.

The outer surface 92a of the board-side connection portion 92 and the outer surface 93a of the resistance-side connection portion 93 intersect with each other so as to be orthogonal to each other, and the inner surface 92b of the board-side connection portion 92 and the inner surface 93b of the resistance-side connection portion 93 are orthogonal to each other. Cross to. Therefore, the substrate-side connecting portion 92 and the resistance-side connecting portion 93 intersect so as to be orthogonal to each other. In the present embodiment, the connecting member 91 is L-shaped when viewed from one end side in the parallel direction F.

In the substrate side connecting portion 92, the direction along the inner surface 92b and orthogonal to the inner surface 93b of the resistance side connecting portion 93 is defined as the protruding direction with respect to the resistance side connecting portion 93. The board-side connecting portion 92 includes a plurality of fixed position adjusting portions 92c arranged in the protruding direction. The fixed position adjusting portion 92c is a hole that penetrates the substrate side connecting portion 92 in the thickness direction. In the present embodiment, the connecting member 91 includes two fixed position adjusting portions 92c.

As shown in FIGS. 2, 6 or 7, the substrate side connection portion 92 is fastened to the wiring pattern of the circuit board 71 by the substrate rivet 94, and the resistance side connection portion 93 is shunted by the resistance rivet 95. It is fastened to the electrode terminal 83 of 81. The substrate rivet 94 penetrates the fixed position adjusting portion 92c of the substrate side connecting portion 92 and the circuit board 71, and fastens the substrate side connecting portion 92 and the circuit board 71. The resistance rivet 95 penetrates the through hole 83a of the shunt resistor 81 and the resistance side connection portion 93, and fastens the electrode terminal 83 and the resistance side connection portion 93.

In each connecting member 91, the outer surface 92a of the substrate-side connecting portion 92 is in contact with the wiring pattern provided on the substrate main surface 71a of the circuit board 71. Further, the outer surface 93a of the resistance side connecting portion 93 is in contact with each electrode terminal 83 via the elastic member 28.

In the current measuring device 50, the substrate-side connecting portion 92 and the circuit board 71 are sandwiched by the substrate rivet 94 in a state of overlapping each other. Due to the sandwiching by the board rivet 94, the board side connection portion 92 and the wiring pattern are in close contact with each other. Due to this close contact, the wiring pattern and the connecting member 91 are electrically connected.

In the current measuring device 50, the resistance side connection portion 93 and the electrode terminal 83 are sandwiched by the resistance rivet 95. Due to the sandwiching by the resistance rivet 95, the electrode terminal 83 and the resistance side connection portion 93 are in close contact with each other, and the shunt resistor 81 is supported by the resistance side connection portion 93. Each resistance rivet 95 is electrically connected to the electrode terminal 83 and also electrically connected to the inner surface 93b of the resistance side connection portion 93. Therefore, each electrode terminal 83 is electrically connected to the connecting member 91 via the resistance rivet 95. The board-side connecting portion 92 of the connecting member 91 is electrically connected to the wiring pattern of the circuit board 71, and the wiring pattern is electrically connected to the voltage amplification IC 72. As a result, the voltage amplification IC 72 amplifies the voltage of the pair of electrode terminals 83 of the resistor 82 to a voltage that can be measured by a microcomputer (not shown), and the microcomputer measures the current flowing through the current path based on the amplified voltage. ..

In the current measuring device 50, the circuit board 71 is accommodated in the accommodating space S of the case 61. One substrate main surface 71a faces and is parallel to the inner surface of the bottom plate 62a of the first case member 62 in the extending direction X. The other substrate main surface 71a of the circuit board 71 faces the lid plate 64 of the second case member 63 in the extending direction X.

In the case 61, the outer surface of the bottom plate 62a of the first case member 62 is along the base main surface 51a of the outer base 51. Therefore, it can be said that the board main surface 71a of the circuit board 71 is parallel to the base main surface 51a of the external base 51. Since the base main surface 51a of the external base 51 is parallel to the first side surface 11c of the power storage unit 11, the substrate main surface 71a of the circuit board 71 is on the first side surface 11c of the power storage unit 11. It is parallel to it. Therefore, the substrate main surface 71a of the circuit board 71 intersects the extension direction X of the negative electrode connection tab 16 protruding from the first side surface 11c. Therefore, the circuit board 71 is arranged adjacent to the power storage unit 11 in a state where the main surface 71a of the board intersects the extension direction X.

Further, the substrate-side connecting portion 92 of each connecting member 91 is arranged in the accommodation space S, and the end portion near the resistance-side connecting portion 93 projects from the communication port 62e to the outside of the case 61. Then, as shown in FIG. 5 or 6, the resistance-side connecting portion 93 of each connecting member 91 is arranged inside the recess 66 of the second case member 63 and is exposed to the outside of the case 61. Since the shunt resistor 81 is connected to the outer surface 93a of the resistance side connecting portion 93 exposed to the outside of the case 61, the shunt resistor 81 is arranged outside the case 61.

The shunt resistor 81 arranged outside the case 61 faces the bottom plate portion 66a of the recess 66. Further, the inner surface 93b of the resistance side connecting portion 93 of each connecting member 91 is supported by the bottom plate portion 66a of the recess 66, and the shunt resistor 81 is supported by the bottom plate portion 66a of the recess 66 via the connecting member 91. .. The shunt resistor 81 may not be supported by the bottom plate portion 66a, but may be supported only by the connecting member 91.

Further, the negative electrode connection tab 16 penetrating the tab insertion hole 51b of the external base 51 is arranged inside the recess 66 of the second case member 63. The negative electrode connection tab 16 overlaps the shunt resistor 81 in the stacking direction D. Specifically, the negative electrode connection tab 16 is arranged outside the stacking direction D with respect to one electrode terminal 83 of the shunt resistor 81. Of the pair of main surfaces 83c of the one electrode terminal 83, one tab surface 16a of the negative electrode connection tab 16 is arranged along the one main surface 83c located outside the stacking direction D. .. Therefore, one main surface 83c of the electrode terminal 83 and one tab surface 16a of the negative electrode connection tab 16 face each other in the stacking direction D.

The connecting hole 83b of the shunt resistor 81 is located at a position where it overlaps with the nut 70 supported by the nut receiving portion 66c of the recess 66. Then, with the one main surface 83c of one electrode terminal 83 and the one tab surface 16a of the negative electrode connection tab 16 aligned, the connection bolt 84 penetrating the negative electrode connection tab 16 penetrates the connection hole 83b. Is screwed into the nut 70. By screwing the connecting bolt 84 and the nut 70, the negative electrode connection tab 16 is fastened to one of the electrode terminals 83 and is electrically connected. That is, one main surface 83c of one electrode terminal 83 and one tab surface 16a of the negative electrode connection tab 16 are in surface contact with each other with a sufficient contact area.

Therefore, one electrode terminal 83 of the shunt resistor 81 and the negative electrode connection tab 16 extending from the power storage unit 11 are in a state of overlapping in the stacking direction D, and the main surface 83c of the electrode terminal 83 and the negative electrode connection tab 16 The tab surface 16a is in surface contact with the tab surface 16a. Therefore, the electrode terminal 83 and the negative electrode connection tab 16 are electrically connected in a state where the electrical resistance is suppressed to a low level.

In the stacking direction D of the power storage unit 11, the position of the tab surface 16a of the negative electrode connection tab 16 and the position of the main surface 83c of the electrode terminal 83 coincide with each other. In this way, the fixed position of the connecting member 91 with respect to the circuit board 71 is adjusted so that the position of the tab surface 16a of the negative electrode connecting tab 16 and the position of the main surface 83c of the electrode terminal 83 coincide with each other.

6 and 7 show two types of power storage units 11. The power storage unit 11 shown in FIG. 6 is referred to as a first power storage unit 11A, and the power storage unit 11 shown in FIG. 7 is referred to as a second power storage unit 11B.

The first power storage unit 11A has a smaller number of power storage modules 12 and conductive plates 13 than the second power storage unit 11B, and the first power storage unit 11A has a smaller dimension in the stacking direction D. When the lower end plate 22 of the first power storage unit 11A and the lower end plate 22 of the second power storage unit 11B are placed on the same surface, the circuit board 71 of the first power storage unit 11A and the second power storage unit The position of the circuit board 71 of 11B is the same. On the other hand, the negative electrode current collector 14 of the first power storage unit 11A and the negative electrode current collector 14 of the second power storage unit 11B are located higher in the negative electrode current collector 14 of the second power storage unit 11B. That is, the negative electrode connection tab 16 of the first power storage unit 11A is located at a position lower than the negative electrode connection tab 16 of the second power storage unit 11B.

In the first power storage unit 11A, in order to align the main surface 83c of the electrode terminal 83 with the tab surface 16a of the negative electrode connection tab 16, the two fixed position adjusting portions 92c of the connecting member 91 are fixed closer to the resistance side connecting portion 93. A substrate rivet 94 is inserted through the position adjusting portion 92c to fix the connecting member 91 to the shunt resistor 81.

On the other hand, in the second power storage unit 11B, in order to align the main surface 83c of the electrode terminal 83 with the tab surface 16a of the negative electrode connection tab 16, the resistance side connection portion 93 of the two fixed position adjusting portions 92c of the connection member 91 The substrate rivet 94 is inserted through the fixed position adjusting portion 92c far from the shunt resistor 81 to fix the connecting member 91 to the shunt resistor 81.

In both the first power storage unit 11A and the second power storage unit 11B, the main surface 83c of one of the electrode terminals 83 and the tab surface 16a of the negative electrode connection tab 16 are in surface contact with each other with a sufficient contact area. doing.

In addition to the first power storage unit 11A and the second power storage unit 11B, the power storage unit 11 may have different dimensions in the stacking direction D. The fixed position adjusting unit 92c may have three or more fixed position adjusting portions 92c so as to correspond to such a plurality of types of power storage units 11, and the fixed position adjusting portion 92c has an elongated hole shape whose length extends in the longitudinal direction of the substrate side connecting portion 92. It may be.

As shown in FIG. 5, a wire harness 88 connected to a load (not shown) is arranged on the other side of the pair of electrode terminals 83 of the shunt resistor 81, and a connecting bolt 84 penetrating the wire harness 88 is connected. It penetrates the hole 83b and is screwed into the nut 70. By screwing the connecting bolt 84 and the nut 70, the wire harness 88 is fastened to the other electrode terminal 83 and is electrically connected.

Next, the operation of the power storage device 10 will be described.
The current flowing in the current path from the power storage unit 11 to the load flows from the negative electrode connection tab 16 of the negative electrode current collector 14 to one electrode terminal 83. Then, the current flows through the pair of electrode terminals 83 and the resistor 82. The voltage generated by the current flowing through the resistor 82 is input to the voltage amplification IC 72 via the resistor rivet 95, the connecting member 91, the substrate rivet 94, and the wiring pattern. The voltage amplification IC 72 amplifies the input voltage, and a microcomputer (not shown) measures the current value based on the amplified voltage value.

In the power storage device 10 in which the power storage unit 11 and the shunt resistor 81 are adjacent to the extension direction X and the substrate main surface 71a of the circuit board 71 intersects the extension direction X, the substrate main surface 71a of the circuit board 71 extends. It does not extend from the power storage unit 11 along the exit direction X, and the power storage device 10 does not become large.

In such a power storage device 10, the negative electrode connection tab 16 and one of the electrode terminals 83 are arranged so that the tab surface 16a and the main surface 83c are in surface contact with each other, and between the negative electrode connection tab 16 and the electrode terminal 83. The tab surface 16a and the main surface 83c are electrically connected in a state where the electrical resistance of the above is suppressed to a low level.

According to the above embodiment, the following effects can be obtained.
(1) For example, in a configuration in which the tab surface 16a of the negative electrode connection tab 16 is orthogonal to the main surface 83c of the electrode terminal 83, in order to reduce the electrical resistance between the negative electrode connection tab 16 and the electrode terminal 83, A separate member having a portion that comes into surface contact with both the tab surface 16a and the main surface 83c is required. However, in the present embodiment, the tab surface 16a and the main surface 83c can be connected in a state of surface contact with each other without the need for a separate member, and the electrode terminal 83 and the negative electrode connection tab 16 can be assembled as compared with the case where a separate member is used. The ease of assembly can be improved, and the assembling property of the power storage unit 11 and the shunt resistor 81 can be improved.

(2) The shunt resistor 81 and the circuit board 71 are electrically connected via the connecting member 91, and the connecting member when the shunt resistor 81 and the circuit board 71 are viewed from one end side in the parallel direction F. 91 has an L shape. In a state where the main surface 83c of the electrode terminal 83 and the tab surface 16a of the negative electrode connection tab 16 are aligned with each other, the substrate main surface 71a of the circuit board 71 is crossed in the extending direction X of the negative electrode connection tab 16 by the connecting member 91. The circuit board 71 can be arranged in this state. For example, as compared with the case where the shunt resistor 81 is connected to the extending portion of the circuit board 71 extending from the substrate main surface 71a to form an L shape in a side view, the shunt resistor 81 is inserted through the connecting member 91. Can suppress heat transfer from the circuit board 71 to the circuit board 71.

(3) The connecting member 91 includes two fixed position adjusting portions 92c on the substrate side connecting portion 92. The position of the shunt resistor 81 with respect to the circuit board 71 can be adjusted by changing the fixed position adjusting portion 92c through which the board rivet 94 is inserted. As a result, the circuit board 71 is attached to the power storage unit 11 at a predetermined mounting position, and even if the position of the negative electrode current collector 14 is changed, the electrode is attached to the tab surface 16a of the negative electrode connection tab 16. It becomes easy to align the main surface 83c of the terminal 83.

(4) The case 61 is provided with a nut receiving portion 66c in the bottom plate portion 66a of the recess 66, and the nut 70 is supported by the nut receiving portion 66c. Therefore, when the negative electrode connection tab 16 is fastened to the electrode terminal 83, the connection bolt 84 inserted into the connection hole 83b of the electrode terminal 83 is easily screwed into the nut 70. Therefore, the tab surface 16a of the negative electrode connection tab 16 and the main surface 83c of the electrode terminal 83 can be arranged along each other, and the electrode terminal 83 and the nut 70 can be easily screwed together. The assembling property between the 81 and the power storage unit 11 can be further improved.

(5) The shunt resistor 81 is supported on the bottom plate portion 66a of the recess 66 via the resistance side connecting portion 93 of the connecting member 91. Therefore, the shunt resistor 81 can be supported in a stable state, and vibration of the shunt resistor 81 due to vibration or the like can be suppressed. As a result, it is easy to maintain a state in which the main surface 83c of the electrode terminal 83 and the tab surface 16a of the negative electrode connection tab 16 are in surface contact with each other.

(6) The connecting member 91 and the shunt resistor 81 are mechanically fastened by the resistance rivet 95, and the connecting member 91 and the circuit board 71 are mechanically fastened by the board rivet 94. Therefore, it is possible to eliminate cracks in the solder due to the influence of heat as in the case where the shunt resistor 81 and the circuit board 71 are solder-connected.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
○ The fixed position adjusting portion 92c of the connecting member 91 may not be provided. In this case, when the main surface 83c of the electrode terminal 83 is aligned with the tab surface 16a of the negative electrode connection tab 16 for the power storage unit 11 having different dimensions in the stacking direction D, the dimension in the longitudinal direction of the substrate side connection portion 92. A plurality of types of connecting members 91 having different values are prepared to cope with the situation.

○ The connecting member 91 may be omitted. In this case, the extension portion orthogonal to the main surface 71a of the substrate is integrally formed from the circuit board 71 so that the shunt resistor 81 and the circuit board 71 are L-shaped when viewed from one end side in the parallel direction F. The shunt resistor 81 may be provided and fixed to the extending portion thereof.

○ The method of connecting the electrode terminal 83 and the negative electrode connection tab 16 may be performed by rivets or welding instead of the connecting bolts 84 and nuts 70.
○ The nut receiving portion 66c and the nut 70 of the bottom plate portion 66a of the recess 66 may be omitted.

○ The method of fastening the electrode terminal 83 of the shunt resistor 81 and the connecting member 91 may be performed with bolts and nuts instead of the resistance rivet 95, or the method of fastening the circuit board 71 and the connecting member 91 may be performed. , The rivet 94 for the substrate may be replaced with bolts and nuts.

○ Even if the board-side connection portion 92 of the connection member 91 and the circuit board 71 are electrically connected by solder, and the resistance-side connection portion 93 of the connection member 91 and the shunt resistor 81 are electrically connected by solder. good.

○ The shunt resistor 81 and the circuit board 71 do not have to be integrated. For example, the shunt resistor 81 may be supported by the bottom plate portion 66a of the second case member 63, and the circuit board 71 may be supported by the bottom plate 62a of the first case member 62.

○ In the power storage device 10, a plurality of power storage modules 12 may be connected in parallel.
○ The positive electrode connection tab 19 of the positive electrode current collector 17 may be electrically connected to one electrode terminal 83 of the shunt resistor 81.

○ In the power storage unit 11, the negative electrode connection tab 16 of the negative electrode current collector 14 protrudes from the first side surface 11c, but the negative electrode connection tab 16 may protrude from the second side surface 11d. In this case, the shunt resistor 81 is arranged adjacent to the second side surface 11d, and the circuit board 71 is arranged so that the substrate main surface 71a is parallel to or substantially parallel to the second side surface 11d.

D ... stacking direction, F ... parallel direction, X ... extension direction, 10 ... power storage device, 11 ... power storage unit, 11c ... short side as side surface, 12 ... power storage module, 14 ... negative electrode current collection as current collector Body, 15 ... Negative electrode current collector body as current collector body, 16 ... Negative electrode connection tab as connection tab, 16a ... Tab surface, 34 ... Bipolar electrode, 71 ... Circuit board, 71a ... Board main surface, 72 ... Measurement Voltage amplification IC as a part, 81 ... Shunt resistor, 82 ... Resistor, 83 ... Electrode terminal, 83c ... Main surface, 91 ... Connection member, 92 ... Board side connection part, 92c ... Fixed position adjustment part, 93 ... Resistance Side connection.

Claims (3)

A power storage module having a plurality of stacked bipolar electrodes,
The current collector main body is laminated in the stacking direction of the bipolar electrodes in the power storage module, and the current collector has a connection tab protruding from the current collector main body in an extension direction intersecting the stacking direction of the current collector main body. With a body and a power storage unit that includes
A shunt resistor having a resistor and a pair of electrode terminals sandwiching the resistor side by side in a parallel direction and adjacent to the power storage unit in the extension direction.
A circuit board on which a measuring unit for measuring the voltage of the pair of electrode terminals is arranged,
The connection tab protrudes along the extension direction from the side surface of the power storage unit that intersects both end faces in the stacking direction, and one of the pair of electrode terminals is connected. A power storage device that is electrically connected to a tab and is adjacent to the power storage unit so that the main surface of the circuit board intersects in the extension direction.
The connection tab has flat tab surfaces on both sides in the stacking direction, and also has a flat tab surface.
The pair of electrode terminals have flat main surfaces on both sides in the thickness direction.
A power storage device characterized in that one of the tab surfaces of the connection tab and the main surface of one of the electrode terminals are connected in surface contact with each other. The shunt resistor and the circuit board are electrically connected via a connecting member, and the connecting member is fixed to the circuit board with a flat plate-shaped resistance-side connecting portion fixed to the shunt resistor. It has a flat plate-shaped substrate-side connection portion, and the resistance-side connection portion and the substrate-side connection portion intersect with each other. The power storage device according to claim 1, wherein the connecting member has an L shape. The power storage device according to claim 2, wherein the substrate-side connecting portion has a plurality of fixed position adjusting portions arranged in a direction protruding from the resistance-side connecting portion.

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