JP2013051175A - Power storage module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage module of simple structure capable of facilitating the replacement work, in which a plurality of secondary cells housed in a battery container and connected by bus bars can be replaced individually.SOLUTION: A bus bar 250 connecting secondary cells 140 consists of a pair of conductive members 251, 252, each having a junction part 260 and a coupling part 270 in which a through hole 271 is formed. In a state where the conductive members 251, 252 are coupled to the through hole 271 of the coupling part 270 by means of a coupling screw 162, the junction parts 260 are welded, respectively, to the positive and negative electrode terminals 140a, 140b of the secondary cell 140. A desired secondary cell 140 can be replaced by removing the coupling screw 162, and then separating the conductive members 251, 252.

Description

  The present invention relates to a power storage module in which a plurality of secondary battery cells are housed in a battery container and electrically connected by a bus bar.

In an energy storage module in which a plurality of secondary battery cells such as lithium ion secondary batteries are housed in a battery container, all the secondary battery cells are connected in series by a connecting conductive member called a bus bar between adjacent secondary battery cells. Connected.
The secondary battery cell and the bus bar are connected to one of the positive and negative terminals of one of the adjacent secondary battery cells, and the other end of the bus bar is connected to the opposite polarity terminal of the other secondary battery cell. By connecting, they are connected in series.

The connection between the bus bar and the positive / negative terminal of the secondary battery cell is generally performed by welding one end of the bus bar directly to the positive / negative terminal of the secondary battery cell by welding. However, in this method, even when only some of the secondary battery cells stored in the battery container are replaced, all the secondary battery cells must be discarded.
Therefore, there is a need for a power storage module that can remove only the secondary battery cell that needs to be replaced and attach a new secondary battery cell.

The following structure is known as an invention in which only the power storage module can be replaced without replacing the protection circuit. However, this prior document does not describe that only some of the secondary battery cells are replaceable among the secondary battery cells housed in the battery container.
A dish-like connection body is welded to each of the positive electrode terminal portion and the negative electrode terminal portion of the secondary battery cell via a ring-shaped insulator. Projections (projections) welded to the positive electrode terminal portion and the negative electrode terminal portion of the secondary battery cell are provided on the lower surface and side surfaces of the dish-like connection body.
The projection provided on the lower surface of the dish-like connection body is welded to the positive electrode terminal portion on the positive electrode side and to the negative electrode terminal portion on the negative electrode side. Moreover, the positive electrode terminal or negative electrode terminal in which the internal thread hole was formed is welded to the projection of the side surface of the dish-shaped connection body welded to the positive electrode terminal part and the negative electrode terminal part, respectively. The end of the bus bar is fastened to each terminal of the positive and negative terminals by a set screw that is screwed into the female screw hole, whereby the bus bar and the secondary battery cell are connected (see, for example, Patent Document 1).

JP 2000-223160 A

  In the structure described in Patent Document 1, a plurality of members such as a dish-like connection body and positive and negative electrode terminals are assembled to the positive electrode terminal portion and the negative electrode terminal portion of the secondary battery cell, so the cost of the secondary battery cell increases. To do. Moreover, since the welding process of welding a plate-shaped connection body and a positive / negative electrode terminal to a positive / negative electrode terminal part, respectively is required, the number of processes also increases.

  The power storage module of the present invention includes a case body having openings on both side surfaces, a plurality of secondary battery cells housed in the case body with the positive and negative terminals facing the opening of the case body, and a secondary battery A pair of case side plates that cover each opening of the case main body in which the battery cells are housed and expose the positive and negative terminals of each secondary battery cell, and the secondary battery cells through the through holes in the case side plate And a bus bar connected to a pair of adjacent secondary battery cells, the bus bar having at least one end bonded to the positive electrode terminal or the negative electrode terminal of the secondary battery cell. The other end of each conductive member is detachably connected to the other conductive member.

  According to the present invention, the bus bar joined to the adjacent secondary battery cell is constituted by a pair of conductive members, and is separated into individual secondary battery cells by detaching the other end side of each conductive member. be able to. Thereby, it becomes possible to remove only the defective secondary battery cell and attach a non-defective secondary battery cell.

The block circuit diagram of the hybrid vehicle drive system as one Embodiment provided with the electrical storage module of this invention. 1 is an external perspective view of a power storage device including a power storage module according to an embodiment of the present invention. The perspective view which looked at the electrical storage apparatus shown in FIG. 2 from the cooling medium entrance side. 1 is an external perspective view of a power storage module according to an embodiment of the present invention. The disassembled perspective view of the electrical storage module shown in FIG. The typical connection diagram which shows the connection state of a secondary battery cell. The top view which shows the structure of a voltage detection conductor. The disassembled perspective view which shows the structure of a bus-bar. The perspective view for demonstrating the method to attach a bus-bar to a case side plate. The processing flowchart which shows the method of replacing | exchanging a secondary battery cell. The disassembled perspective view of the bus-bar of Embodiment 2 of this invention. The disassembled perspective view of the bus-bar of Embodiment 3 of this invention. The perspective view of the bus-bar which concerns on Embodiment 4 of this invention. The top view of the voltage detection conductor which concerns on Embodiment 4 of this invention. It is a figure for demonstrating the attachment method of the bus-bar which concerns on Embodiment 4 of this invention, (A) is a first process, (B) is a perspective view for demonstrating the process following (A). The perspective view of the bus-bar of Embodiment 5 of this invention.

--Embodiment 1--
Hereinafter, a power storage module according to an embodiment of the present invention will be described in detail with reference to the drawings.
Below, the case where the power storage module according to one embodiment is applied to a power storage device constituting an in-vehicle power supply device of an electric vehicle, particularly an electric vehicle will be described as an example. The electric vehicle includes a hybrid electric vehicle including an engine that is an internal combustion engine and an electric motor as a driving source of the vehicle, and a genuine electric vehicle using the electric motor as the only driving source of the vehicle.
A hybrid vehicle drive system to which the power storage module of the present invention is applied will be described.

[Hybrid car drive system]
FIG. 1 is a block circuit diagram of a hybrid vehicle drive system having a power storage module as one embodiment of the present invention. The hybrid vehicle drive system shown in FIG. 1 illustrates an in-vehicle electric system as an example, and includes a motor generator 10, an inverter device 20, a vehicle controller 30 that controls the entire vehicle, a power storage device 1000 that constitutes an in-vehicle power supply device, and the like. Is provided. The power storage device 1000 is configured as, for example, a lithium ion battery device including a plurality of secondary battery cells.

  The motor generator 10 is a three-phase AC synchronous machine. The motor generator 10 is driven by a motor in an operation mode that requires rotational power, such as when the vehicle is powered and when an engine that is an internal combustion engine is started, and the generated rotational power is supplied to a driven body such as a wheel and an engine. . In this case, the in-vehicle electric system converts DC power into three-phase AC power and supplies it to the motor generator 10 via the inverter device 20 that is a power converter from the power storage device 1000.

  The motor generator 10 is driven by a driving force from a wheel or an engine in an operation mode that requires power generation, such as when the vehicle is decelerating or braking, or when the power storage device 1000 needs to be charged. To generate three-phase AC power. In this case, the in-vehicle electric system converts the three-phase AC power from the motor generator 10 into DC power via the inverter device 20 and supplies it to the power storage device 1000. As a result, power is stored in power storage device 1000.

  The inverter device 20 is an electronic circuit device that controls the above-described power conversion, that is, conversion from DC power to three-phase AC power, and conversion from three-phase AC power to DC power by operation (on / off) of a switching semiconductor element. It is. The inverter device 20 includes a power module 21, a driver circuit 22, and a motor controller 23.

The power module 21 is a power conversion circuit that includes six switching semiconductor elements and performs the above-described power conversion by switching operations (on / off) of the six switching semiconductor elements.
The DC positive module terminal is electrically connected to the DC positive external terminal, and the DC negative module terminal is electrically connected to the DC negative external terminal. The DC positive side external terminal and the DC negative side external terminal are power supply side terminals for transmitting and receiving DC power to and from the power storage device 1000, and power cables 610 and 620 extending from the power storage device 1000 are electrically connected. Yes. The AC side module terminal is electrically connected to the AC side external terminal. The AC side external terminal is a load side terminal for transmitting and receiving three-phase AC power to and from the motor generator 10, and a load cable extending from the motor generator 10 is electrically connected thereto.

  The motor controller 23 is an electronic circuit device for controlling the switching operation of the six switching semiconductor elements constituting the power conversion circuit. The motor controller 23 generates switching operation command signals (for example, PWM (pulse width modulation) signals) for the six switching semiconductor elements based on a torque command output from a host controller, for example, a vehicle controller 30 that controls the entire vehicle. To do. The generated command signal is output to the driver circuit 22.

The power storage device 1000 is a power storage module 100a, 100b for storing and discharging electrical energy (charging / discharging DC power), and a control device 900 for managing and controlling the state of the power storage modules 100a, 100b (see FIG. 2). It has.
The power storage modules 100a and 100b are high-potential side and low-potential side power storage modules that are electrically connected in series, respectively. Each power storage module 100a, 100b has secondary battery cells such as a plurality of lithium ion secondary batteries connected in series. Although details will be described later, the plurality of secondary battery cells are connected in series by a bus bar to form first and second battery cell rows. The configuration of each power storage module 100a, 100b will be described later.

  An SD (service disconnect) switch 700 is provided between the negative electrode side (low potential side) of the high potential side power storage module 100a and the positive electrode side (high potential side) of the low potential side power storage module 100b. The SD switch 700 is a safety device provided to ensure safety during maintenance and inspection of the power storage device 1000. The SD switch 700 includes an electric circuit in which a switch and a fuse are electrically connected in series. Operated during maintenance and inspection.

The control device 900 includes a battery controller 300 corresponding to the upper (parent) and a cell controller 310 corresponding to the lower (child).
The battery controller 300 manages and controls the state of the power storage device 1000, and notifies the vehicle controller 30 and the motor controller 23, which are host control devices, of charge / discharge control commands such as the state of the power storage device 1000 and allowable charge / discharge power. The management and control of the state of the power storage device 1000 includes the measurement of the voltage and current of the power storage device 1000, the calculation of the power storage state (SOC: State Of Charge) and the deterioration state (SOH: State Of Health), Measurement of the temperature of the power storage module, output of a command to the cell controller 310 (for example, a command for measuring the voltage of each secondary battery cell, a command for adjusting the power storage amount of each secondary battery cell, etc.), and the like.

  The cell controller 310 is a limb of the so-called battery controller 300 that manages and controls the states of a plurality of lithium-in on secondary battery cells according to instructions from the battery controller 300, and is configured by a plurality of integrated circuits (ICs). Yes. The management and control of the state of the plurality of secondary battery cells include measurement of the voltage of each secondary battery cell, adjustment of the amount of electricity stored in each secondary battery cell, and the like. That is, although not shown in FIG. 1, the cell controller 310 includes a voltage sensor that measures the voltage of each secondary battery cell. The voltage sensor is configured by an operational amplifier connected to the positive terminal and the negative terminal of each secondary battery cell in the power storage modules 100a and 100b. The output voltage from the operational amplifier is converted from an analog value to a digital value by an A / D converter (not shown) built in the cell controller 310. In addition, a discharge circuit (not shown) in which a resistor and a switching element are connected in series is connected in parallel to the positive terminal and the negative terminal of each secondary battery cell. When each secondary battery cell or the average value of the secondary battery cells exceeds a predetermined voltage value, the switching element is turned on by a command from the cell controller 310 and is discharged until the voltage value becomes equal to or lower than the predetermined voltage value. As described above, each integrated circuit has a plurality of corresponding secondary battery cells, and performs state management and control on the corresponding secondary battery cells.

A plurality of corresponding secondary battery cells are used as the power source of the integrated circuit constituting the cell controller 310. Therefore, both the cell controller 310 and the power storage module 100 are electrically connected via the connection wiring 800. The voltage of the highest potential of the corresponding secondary battery cells is applied to each integrated circuit via the connection wiring 800.
Both the positive terminal of the high-potential-side power storage module 100a and the DC positive-side external terminal of the inverter device 20 are electrically connected via a positive-side power cable 610. The negative electrode terminal of the low-potential-side power storage module 100 b and the DC negative electrode-side external terminal of the inverter device 20 are electrically connected via a negative-side power cable 620.

  A junction box 400 and a negative main relay 412 are provided in the middle of the power cables 610 and 620. Inside the junction box 400, a relay mechanism including a positive-side main relay 411 and a precharge circuit 420 is housed. The relay mechanism is an opening / closing unit for electrically connecting and disconnecting the power storage modules 100a and 100b and the inverter device 20, and between the power storage modules 100a and 100b and the inverter device 20 when the on-vehicle electric system is started. The power storage modules 100a and 100b are disconnected from the inverter device 20 when continuity occurs and when the on-vehicle electric machine system is stopped or abnormal. Thus, by controlling between the power storage device 1000 and the inverter device 20 by the relay mechanism, high safety of the in-vehicle electric system can be ensured.

  The driving of the relay mechanism is controlled by the motor controller 23. The motor controller 23 receives a notification of the completion of the activation of the power storage device 1000 from the battery controller 300 when the on-vehicle electric system is activated, thereby driving the relay mechanism by outputting a conduction command signal to the relay mechanism. The motor controller 23 receives an output signal from the ignition key switch when the in-vehicle electric system is stopped, and receives an abnormal signal from the vehicle controller when the in-vehicle electric system is abnormal. A relay command is driven by outputting a shutoff command signal.

  The main relay includes a positive side main relay 411 and a negative side main relay 412. Positive-side main relay 411 is provided in the middle of positive-side power cable 610, and controls electrical connection between the positive-electrode side of power storage device 1000 and the positive-electrode side of inverter device 20. The negative-side main relay 412 is provided in the middle of the negative-side power cable 620, and controls electrical connection between the negative-electrode side of the power storage device 1000 and the negative-electrode side of the inverter device 20.

The precharge circuit 420 is a series circuit in which a precharge relay 421 and a resistor 422 are electrically connected in series, and is electrically connected to the positive-side main relay 411 in parallel.
When starting the in-vehicle electric system, first, the negative side main relay 412 is turned on, and then the precharge relay 421 is turned on. Thus, the current supplied from the power storage device 1000 is limited by the resistor 422, and then supplied to the smoothing capacitor mounted on the inverter and charged. After the smoothing capacitor is charged to a predetermined voltage, the positive main relay 411 is turned on and the precharge relay 421 is opened. Thereby, main current is supplied from power storage device 1000 to inverter device 20 via positive-side main relay 411.

  A current sensor 430 is housed in the junction box 400. Current sensor 430 is provided to detect a current supplied from power storage device 1000 to inverter device 20. The output line of the current sensor 430 is electrically connected to the battery controller 300. Battery controller 300 detects the current supplied from power storage device 1000 to inverter device 20 based on the signal output from current sensor 430. This current detection information is notified from the battery controller 300 to the motor controller 23, the vehicle controller 30, and the like.

  The current sensor 430 may be installed outside the junction box 400. The current detection part of the power storage device 1000 may be not only the inverter device 20 side of the positive main relay 411 but also the power storage module 100 a side of the positive main relay 411.

  A voltage sensor for detecting the voltage value charged in each secondary battery cell may be housed in the junction box 400. When the voltage sensor is housed in the junction box 400, the output line of the voltage sensor is connected to the positive / negative terminal of each secondary battery cell via the battery controller 300 in the same manner as the current sensor 430. Battery controller 300 detects the overall voltage of power storage device 1000 based on the output signal of the voltage sensor. This voltage detection information is notified to the motor controller 23 and the vehicle controller 30.

[Structure of power storage device]
2 and 3 are perspective views illustrating the overall configuration of the power storage device 1000. FIG. 2 is a diagram viewed from the outlet side of the cooling medium of power storage device 1000, and FIG. 3 is a diagram viewed from the inlet side of the cooling medium. The power storage device 1000 is roughly divided into two units: power storage modules 100a and 100b and a control device 900. First, the configuration of the power storage modules 100a and 100b will be described.

  As described above, the power storage modules 100a and 100b are high-potential-side and low-potential-side power storage modules, respectively. The power storage modules 100a and 100b are electrically connected in series, and a plurality of secondary battery cells. Is stored. As shown in FIG. 2, the high potential side power storage module 100 a and the low potential side power storage module 100 b are arranged adjacent to each other in parallel so that the longitudinal directions of the blocks are parallel to each other.

The high-potential-side power storage module 100a and the low-potential-side power storage module 100b are juxtaposed on the module base 101 and fixed by fixing means such as bolts. The module base 101 is composed of a rigid thin metal plate (for example, an iron plate) that is divided into three in the lateral direction, and is fixed to the vehicle. That is, the module base 101 is composed of three members arranged at both ends and the center in the short direction. With such a configuration, the surface of the module base 101 can be flush with the lower surfaces of the power storage modules 100a and 100b, and the dimensions in the height direction of the power storage modules 100a and 100b can be further reduced.
The upper portions of the high potential side power storage module 100a and the low potential side power storage module 100b are fixed by a casing 910 of the control device 900 described later.
Note that the high potential side power storage module 100a and the low potential side power storage module 100b basically have the same structure. Therefore, in the following description, the high-potential-side power storage module 100a and the low-potential-side power storage module 100b will be described as the power storage module 100.

[Power storage module]
(Battery container)
FIG. 4 is an external perspective view of the power storage module 100 constituting the power storage device 1000. FIG. 5 is an exploded perspective view of the power storage module 100.
As illustrated in FIG. 5, the power storage module 100 includes a case body 110, a pair of case side plates 130 and 131 disposed on both side surfaces of the case body 110, and a pair of cover plates 160 disposed on the outside of each case side plate. The battery container comprised from these. Sixteen secondary battery cells 140 are accommodated in the battery container. The 16 secondary battery cells 140 are configured to be electrically connected in series by a plurality of bus bars, which will be described later.

The case main body 110 constitutes a substantially hexahedral block housing whose both side surfaces are opened.
Specifically, the inlet channel forming part 111 (see FIGS. 4 and 5), the outlet channel forming part 118 (see FIGS. 4 and 5), the inlet side guide part 112 (see FIG. 3) and the outlet side guide part 113 ( 4 and 5). The internal space of the case body 110 functions as a storage chamber in which a plurality of secondary battery cells 140 are stored, and as a cooling passage through which a cooling medium (cooling air) for cooling the secondary battery cells 140 flows. Function.
In the following description, the direction in which the length of the case body 110 is the longest and the direction from the inlet side guide part 112 side to the outlet side guide part 113 side are defined as the longitudinal direction.
The direction in which the two case side plates 130 and 131 face each other is defined as the short direction. The axis of the secondary battery cell 140 (the direction in which the two electrodes of the positive electrode terminal and the negative electrode terminal face each other) faces in the short direction.
Furthermore, the direction in which the inlet channel forming unit 111 and the outlet channel forming unit 118 face each other is defined as the height direction regardless of the installation direction of the power storage module 100.

  The inlet channel forming portion 111 is a rectangular flat plate portion that forms the upper surface of the case body 110. The outlet channel forming portion 118 is a flat plate portion that forms the bottom surface of the case main body 110. The inlet channel forming part 111 and the outlet channel forming part 118 have substantially the same overall length, but the positions of the end portions in the longitudinal direction are shifted from each other in the longitudinal direction.

The entrance side guide part 112 is a plate-like part that forms one side of the side surface of the case body 110 that faces the longitudinal direction. The outlet side guide portion 113 is a plate-like portion that forms the other side of the side surface facing the longitudinal direction of the case main body 110.
The inlet channel forming part 111, the outlet channel forming part 118, the inlet side guide part 112, and the outlet side guide part 113 are integrally formed as a case main body 110 by, for example, an aluminum die casting method.
A cooling medium inlet 114 (see FIG. 3) is formed between the inlet flow path forming part 111 and the inlet side guide part 112, which constitutes an inlet for introducing cooling air, which is a cooling medium, into the case body 110. .

As described above, the inlet flow path forming portion 111 and the outlet flow path forming portion 118 are arranged such that their longitudinal ends are shifted in the longitudinal direction. The amount of deviation of the end portion in the longitudinal direction is ½ of the pitch of the secondary battery cells 140 in the longitudinal direction, and a step corresponding to the amount of deviation is formed at the inlet side end portion of the case body 110. For this reason, a space is formed between the coolant inlet 114 and the inlet guide 112 in the longitudinal direction. In this space, a gas discharge pipe 139 (see FIG. 3) is arranged.

With such a configuration, the longitudinal dimension of the power storage module 100 can be shortened.
Between the outlet flow path forming part 118 and the outlet side guide part 113, a cooling medium outlet 115 for leading cooling air from the inside of the case body 110 is formed. The cooling medium outlet 115 is provided with a cooling medium outlet duct 117 (see FIGS. 4 and 5) for guiding the cooling air from the cooling medium outlet 115 to the outside.

  The positions of the cooling medium inlet 114 and the cooling medium outlet 115 are shifted in the height direction. That is, in the height direction, the cooling medium inlet 114 is located on the inlet flow path forming part 111 side, and the cooling medium outlet 115 is located on the outlet flow path forming part 118 side.

The case side plates 130 and 131 are arranged to face the case body 110 in the short direction.
Each of the case side plates 130 and 131 is a substantially flat member, and is a molded body made of a synthetic resin such as PBT (polybutylene terephthalate) having electrical insulation.
A cover plate 160 called a side cover is provided on the outside of the case side plates 130 and 131, that is, on the side opposite to the storage chamber in which the secondary battery cell 140 is stored. The cover plate 160 is fixed to the case side plates 130 and 131 by bolts 161 (see FIG. 4).

  The cover plate 160 is a flat plate formed by pressing a metal plate such as iron or aluminum, or a flat plate formed by molding a resin such as PBT, and is configured in substantially the same shape as the planar shape of the case side plates 130 and 131. . The cover plate 160 uniformly swells toward the opposite side of the case side plate 130, that is, toward the outside of the case main body 110, that is, the inner side of the central portion, that is, the peripheral portion. Thereby, a space is formed between the cover plate 160 and the case side plates 130 and 131. This space functions as a gas discharge passage through which mist-like gas ejected from the secondary battery cell 140 due to overcharge / discharge or the like is released separately from the cooling medium flowing through the cooling passage.

(Battery cell storage structure)
The 16 secondary battery cells 140 are stored in alignment in a storage chamber formed inside the case body 110, and are sandwiched by the case side plates 130 and 131 from the short side direction, and are electrically conductive such as copper. They are electrically connected in series by a bus bar 250 made of a good material.
The secondary battery cell 140 is a cylindrical, for example, lithium ion secondary battery in which a positive electrode terminal 140a is formed on one end side and a negative electrode terminal 140b is formed on the other end side, and a non-aqueous electrolyte is injected. Components such as a power generation unit and a safety valve are housed inside the battery can.

Although not shown, a safety valve is formed on the positive electrode terminal 140a side in the battery can that is torn when the pressure inside the battery container reaches a predetermined pressure due to an abnormality such as overcharge.
The safety valve functions as a fuse mechanism that cuts off the electrical connection between the battery lid and the positive electrode side of the battery element when it is cleaved, and the gas generated inside the battery container, that is, a mist-like carbonate system containing a non-aqueous electrolyte It functions as a decompression mechanism that ejects gas to the outside of the battery container.

The battery can has a cylindrical shape in which an opening for fitting a battery lid serving as the positive electrode terminal 140a is formed in the upper part, and the whole is a negative electrode. Usually, the bottom of the battery can is used as a negative electrode terminal. Also in this embodiment, the case where the bottom of the can is the negative electrode terminal 140b will be described.
The battery can which is the negative electrode side and the battery lid which is the positive electrode terminal are insulated by a gasket (not shown) made of an insulating material.
A safety valve is also provided on the negative electrode terminal 140b which is the bottom of the battery can. This safety valve is formed by forming a groove having a V-shaped cross section by pressing the can bottom of the secondary battery cell 140. For example, the secondary battery cell 140 has a nominal output voltage of 3.0 to 4.2 volts and an average nominal output voltage of 3.6 volts.

  In one embodiment, 16 cylindrical secondary battery cells 140 are arranged in alignment inside the case body 110. Specifically, the secondary battery cell 140 is turned sideways, in other words, the axis of the secondary battery cell 140 is arranged in parallel to the short side direction, and eight secondary battery cells 140 are arranged along the longitudinal direction. The first battery cell row 121 is configured in parallel on the upper side. Similarly to the first battery cell row 121, eight secondary battery cells 140 are arranged in parallel on the lower side along the longitudinal direction to form the second battery cell row 122. That is, inside the case main body 110, eight secondary battery cells 140 are arranged in two stages in the longitudinal direction and in the height direction. A battery cell array 120 is constituted by the first battery cell array 121 and the second battery cell array 122.

The first battery cell row 121 and the second battery cell row 122 are displaced from each other in the longitudinal direction. That is, the first battery cell row 121 is arranged on the inlet flow path forming portion 111 side with respect to the second battery cell row 122 and shifted to the cooling medium inlet 114 side. On the other hand, the second battery cell row 122 is arranged closer to the outlet flow path forming portion than the first battery cell row 121 and to the cooling medium outlet 115 side.
As shown in FIG. 5, in one embodiment, for example, the position in the longitudinal direction of the central axis of the secondary battery cell 140 located closest to the cooling medium outlet 115 in the first battery cell row 121 is the second battery cell row. 122, the first battery cell row 121 and the intermediate battery between the central axis of the secondary battery cell 140 located closest to the cooling medium outlet 115 and the central axis of the secondary battery cell 140 adjacent thereto. The second battery cell row 122 is arranged shifted in the longitudinal direction.

  The secondary battery cells 140 constituting the first battery cell row 121 are arranged with the axial centers in parallel so that the positive terminals 140a and the negative terminals 140b are alternately reversed. Similarly, the secondary battery cells 140 constituting the second battery cell row 122 are also arranged with the axial centers in parallel so that the positive terminals 140a and the negative terminals 140b are alternately reversed. However, the order of arrangement of the positive and negative terminals 140a and 140b of the secondary battery cells 140 constituting the first battery cell row 121 from the cooling medium inlet 114 (see FIG. 3) side to the cooling medium outlet 115 side is the second battery. This is different from the arrangement order of the terminals of the secondary battery cells 140 constituting the cell row 122.

That is, in the first battery cell row 121, the terminals of the secondary battery cells 140 facing the case side plate 130 side are the negative electrode terminal 140b, the positive electrode terminal 140a, and the negative electrode terminal from the cooling medium inlet 114 side to the cooling medium outlet 115 side. 140b,..., And positive electrode terminal 140a are arranged in this order. On the other hand, in the second battery cell row 122, the terminals of the secondary battery cells 140 facing the case side plate 130 side are positive terminal 140a, negative terminal 140b, positive terminal from the cooling medium inlet 114 side to the cooling medium outlet 115 side. 140a, ..., negative electrode terminal 140b are arranged in this order.
As described above, by disposing the first battery cell row 121 and the second battery cell row 122 in the longitudinal direction, the size in the height direction of the case body 110 can be reduced, and the power storage module 100 can be moved in the height direction. It can be downsized.

(Battery cell connection)
The 16 secondary battery cells 140 housed in the case body 110 are all connected in series by bus bars 250, 250a, 250b, which will be described later.
FIG. 6 is a schematic connection diagram illustrating a connection state of the secondary battery cells. In FIG. 6, the second battery cell row 122 on the lower stage side is composed of eight secondary battery cells BC1 to BC8. The first battery cell row 121 on the upper stage side is composed of eight secondary battery cells BC9 to BC16.
The negative electrode of the secondary battery cell BC1 and the positive electrode of BC2, the negative electrode of BC3 and the positive electrode of BC4, and the negative electrode of BC13 and the positive electrode of BC14 are the case side plates on the front side of the case body 110 shown in FIG. The bus bars W1 to W7 attached to 130 are connected. The negative electrode of the secondary battery cell BC2 and the positive electrode of BC3, the negative electrode of BC4 and the positive electrode of BC5, and the negative electrode of BC14 and the positive electrode of BC15 are the case side plates on the back side of the case body 110 shown in FIG. The bus bars W8 to W15 attached to 131 are connected.

The positive electrode of the secondary battery cell BC16 is the highest potential part of the power storage modules 100a and 100b, and is connected to a connection terminal 180 (see FIGS. 5 and 6) integrally formed on the case side plate 130 as will be described later via the bus bar 250a. Connected. The negative electrode of the secondary battery cell BC15, the lowest potential part of the power storage modules 100a and 100b, and the connection terminal 181 (see FIGS. 5 and 6) integrally formed on the case side plate 130 as will be described later via the bus bar 250b. Connected.
In this way, all the 16 secondary battery cells 140 housed in each power storage module 100 are connected in series.

(Case side plate)
Next, the structure of the pair of case side plates 130 and 131 that sandwich the first battery cell row 121 and the second battery cell row 122 from both sides will be described. Here, only the structure of one case side plate 130 will be described, but the other case side plate 131 is basically configured similarly to the case side plate 130.

In describing the structure of the case side plates 130 and 131, returning to FIG. 1, the power storage module 100 will be described by dividing it into a high potential side power storage module 100a and a low potential side power storage module 100b.
The positive-side input / output terminal (not shown) of the high-potential-side power storage module 100a is connected to the terminal of the positive-side power cable 610 (see FIG. 1), and the negative-side input / output terminal is connected to one end of the SD switch 700. The terminal of the cable electrically connected to the side is connected. The terminal of the cable electrically connected to the other end side of the SD switch 700 is connected to the positive electrode side input / output terminal of the low potential side power storage module 100b. The terminal of the negative power supply cable 620 (see FIG. 1) is connected to the negative input / output terminal of the low potential storage module 100b. In FIG. 2, the sub-assemblies 185 of the high-potential side power storage module 100 a and the low-potential side power storage module 100 b are covered with the terminal covers.

As shown in FIG. 5, the case side plate 130 is formed in a substantially rectangular flat plate shape.
The case side plate 130 has a side portion having a predetermined thickness on the outer peripheral portion, and 16 side plate through holes (through holes) 132 for accommodating the secondary battery cells 140 are formed inside the side portion. ing. Each side plate through-hole 132 is formed in a circular shape slightly smaller than the outer diameter of the secondary battery cell 140.
The 16 side plate through-holes 132 correspond to the eight side plate through-holes 132 in which the eight side plate through-holes 132 corresponding to the lower second battery cell row 122 correspond to the upper first battery cell row 121. Thus, the secondary battery cells 140 are arranged so as to be closer to the cooling medium outlet 115 by a (1/2) pitch.

  When the 16 secondary battery cells 140 are accommodated in the case body 110, all the 16 side plate through holes 132 of the case side plate 130 are closed by the positive terminal 140a or the negative terminal 140b of the secondary battery cell 140. It is. Similarly, the 16 side plate through-holes 132 on the case side plate 131 side are all closed by one of the positive and negative terminals 140a and 140b of any one of the secondary battery cells 140 (not shown). However, the secondary battery cell 140 terminal in which the side plate through hole 132 of the case side plate 130 is closed and the secondary plate cell 132 in the case side plate 131 corresponding to the side plate through hole 132 of the case side plate 130 are closed. The positive electrode and the negative electrode are opposite to the terminal of the battery cell 140.

The diameter of each side plate through-hole 132 is formed slightly smaller than the diameter of the positive electrode terminal 140a and the negative electrode terminal 140b, and a part of each of the positive electrode terminal 140a and the negative electrode terminal 140b is exposed.
Although not shown, on the inner surface side of the case side plate 130, ring-shaped ribs having a larger diameter than the through holes are formed corresponding to the side plate through holes 132. The ring-shaped rib serves as a guide member when the secondary battery cell 140 is stored, and also functions as a holding member that holds the secondary battery cell 140 after storage.

Each secondary battery cell 140 held by a rib formed corresponding to each side plate through-hole 132 of the case side plate 130 has the peripheral portions of the positive and negative electrode terminals 140a and 140b at the inner side of the rib and the side plate through-hole. The adhesive is applied to the case side plate 130 with an adhesive applied to a groove (not shown) formed between it and 132.
Therefore, the cooling medium flowing through the case body 110 from the cooling medium inlet 114 toward the cooling medium outlet 115 is blocked by an adhesive that bonds the positive / negative terminal 140a or 140b to the inner surface of the case side plate 130. It does not flow out to the outer surface side of the side plate 130.

  Due to overcharge to the secondary battery cell 140, the internal pressure in the secondary battery cell 140 increases, the cleavage valve breaks, and a mist-like gas (including electrolyte solution etc.) is generated from the inside of the secondary battery cell 140. (Gas mixed with liquid and gas) may be ejected or leaked. This mist-like gas is ejected into the internal space formed by the case side plate 130 and the cover plate 160. However, even in such a case, the mist-like gas is blocked by the adhesive that bonds the positive / negative terminal 140a or 140b to the inner surface of the case side plate 130, and does not flow into the inner side of the case side plate 130.

  A groove 134 is formed in a side facing the cover plate 160 on a side portion formed on the outer peripheral portion of the case side plate 130, and an O-ring 135 is fitted in the groove 134. The O-ring 135 is an annular seal member having elasticity. A liquid gasket may be used for the O-ring 135.

As illustrated in FIG. 5, a bus bar 250 that connects the positive terminal 140 a and the negative terminal 140 b of the adjacent secondary battery cell 140 is disposed between the case side plate 130 and the cover plate 160. Details of the bus bar 250 will be described later.
Between the side plate through-holes 132 in the outer wall surface 170 of the case side plate 130, a plurality of female screw portions 130a for arranging the bus bar 250 connected to the secondary battery cell 140 are formed. The female screw portion 130 a is formed between a pair of positive terminal 140 a and negative terminal 140 b connected by the bus bar 250. As will be described later, the bus bar 250 is attached to the case side plate 130 or 131 by inserting a connecting screw (fastening member) 162 through a through hole provided in the bus bar 250 and fastening it to the female screw portion 130a.

  On the outer wall surface 170 side of the case side plate 130, a rib 136 is formed on the outer edge of the side plate through hole 132. The rib 136 is formed in an approximately eight shape so as to connect the pair of side plate through holes 132 adjacent to the female screw portion 130a. The rib 136 and the female screw portion 130 a also have a function of preventing contact between the cover plate 160 made of a conductive material and the bus bar 250.

(Gas discharge passage)
The case side plate 130 is provided with a gas discharge passage 138 (see FIG. 5) for discharging the mist-like gas released into the gas discharge chamber between the case side plate 130 and the cover plate 160 to the outside of the power storage module 100. It has been. The opening of the gas discharge passage 138 is formed with the case side plate 130 in consideration of the discharge of mist-like gas ejected from the cleavage valves of the positive and negative terminals 140 a and 140 b of the secondary battery cell 140 to the outer wall surface 170 of the case body 110. It is formed in the lower part. Specifically, it is formed on the case side plate 130 on the cooling medium inlet 114 side of the case side plate 130 and on the outlet flow path forming portion 118 side. A distal end portion of the gas discharge passage 138 is formed in a tubular shape, and a gas discharge pipe 139 (see FIG. 3) for guiding the gas discharged from the gas discharge passage 138 to the outside is connected.

  Two connection terminals 810 are provided side by side in the longitudinal direction on the upper surface of the case side plate 130, that is, the surface on the inlet flow path forming portion 111 side. The connection terminal 810 is integrally formed with the case side plate 130 by insert molding, and is disposed on the cooling medium inlet 114 side on the upper surface of the case side plate 130.

(Voltage detection conductor)
Each connection terminal 810 includes a current interrupting unit 811 (see FIGS. 2 and 3), a connection wiring 800 extending from a voltage detection connector 912 (see FIGS. 2 and 3) of the control device 900, and a voltage detection to be described later. The conductor 805 is electrically connected through the current interrupting portion 811.

  The voltage detection connectors 912 are respectively installed at both ends of the control device 900 in the short direction. The connection wiring 800 connected to the connection terminal 810 provided in the high potential side power storage module 100a is connected to the voltage detection connector 912 of the control device 900 disposed above the high potential side power storage module 100a. . On the other hand, the connection wiring 800 connected to the connection terminal 810 provided on the low potential side power storage module 100b is connected to the voltage detection connector 912 of the control device 900 disposed above the low potential side power storage module 100b. Is done. The length of the connection wiring 800 is set to correspond to the distance from each connection terminal 810 to the corresponding voltage detection connector 912 in order to prevent a wiring error. For example, the connection wiring 800 connected to the connection terminal 810 of the high-potential-side power storage module 100a is set so as not to reach the voltage detection connector 912 for the low-potential-side power storage module 100b. The current interrupting unit 811 includes a fuse wire, and has a function of protecting the product by cutting off the current from each secondary battery cell 140 by melting when the control device 900 or the connection wiring 800 is abnormal.

  The voltage detection conductor 805 is connected to each bus bar 250 that connects the secondary battery cells 140 in series in order to detect the battery voltages of the 16 secondary battery cells 140. The voltage detection conductor 805 is integrated with the case side plate 130. Specifically, it is embedded in the case side plate 130.

  As shown in FIG. 7, the voltage detection conductor 805 includes a long and thin rectangular detection line (wiring) 806 formed by pressing a thin metal plate such as copper. The detection line 806 constituting the voltage detection conductor 805 has a connection pad 800a connected to the bus bars 250, 250a, 250b. A female thread is formed in the approximate center of each connection pad 800a.

  The shape of the voltage detection conductor 805 is designed to efficiently use the available space of the case side plate 130 so as to reduce the size of the case side plate 130 and the entire storage module 100. In addition, since the plurality of secondary battery cells 140 are connected in series via the bus bar 250, a potential difference is generated between the plurality of bus bars 250 to which the voltage detection conductor 805 is connected. Therefore, the arrangement of the detection lines 806 is determined so that the potential difference between the adjacent detection lines 806 is as small as possible.

  The detection line 806 is formed into a predetermined shape by pressing or the like, and then fixed by a resin portion 807 made of the same resin as the case side plate 130, for example. One end and the other end of the detection line 806 fixed by the resin portion 807 are connected to the connection pad 800a, and the connection pads 800a are connected to the connection terminals 180 and 181, respectively. Thus, the voltage detection illustrated in FIG. A conductor 805 is formed.

(Bus bar structure and installation)
FIG. 8 is an exploded perspective view showing the configuration of the bus bar 250.
Each bus bar 250 includes a pair of conductive members 251 and 252.
The conductive members 251 and 252 are formed, for example, by pressing a metal plate such as copper.
Each of the conductive members 251 and 252 has a joint portion (one end) 260 joined to the secondary battery cell 140 and a connecting portion (the other end) 270 bent from the joint portion 260 stepwise. An elongated through-hole 261 is formed at substantially the center of the joint 260, and joint portions 262 are formed on both sides of the through-hole 261. A through hole 271 is formed at the distal end side of the connecting portion 270.

FIG. 9 is a perspective view for explaining a method of attaching the bus bar 250 to the case side plate 130.
The case side plate 130 is formed with a female screw portion 130a. A female screw formed on the connection pad 800a of the voltage detection conductor 805 is provided concentrically on the female screw part 130a.
The through holes 271 of the conductive members 251 and 252 are concentric, and the connecting portions 270 of the conductive members 251 and 252 are overlapped. In this state, the connecting screw 162 is inserted through the through holes 271 of the conductive members 251 and 252 and fastened to the female screw portion 130 a of the case side plate 130 and the female screw of the connection pad 800 a of the voltage detection conductor 805. The conductive members 251 and 252 are positioned so that the joint portions 262 of the conductive members 251 and 252 correspond to the joint portions of the secondary battery cell 140 housed in the case side plate 130, and the connecting screw 162 is firmly fastened. . Thereafter, the joining portions 262 of the conductive members 251 and 252 are joined to the positive and negative terminals 140a and 140b of the secondary battery cell 140 exposed from the side plate through-hole 132, respectively, so that the adjacent secondary battery cells 140 are joined. Are connected in series.

Similarly, the bus bar 250 is attached to the case side plate 131 attached to the back side of the case main body 110 and joined to the secondary battery cell 140.
In this way, as illustrated in FIG. 6, the power storage module 100 is configured in which 16 secondary battery cells 140 are connected in series.
And on the front side of case body 110, bus bar 250a is joined to positive electrode terminal 140a of secondary battery cell BC16, and bus bar 250b is joined to negative electrode terminal 140b of secondary battery cell BC15.
The bus bars 250a and 250b also have a joint portion 262 and through holes 261 and 271 respectively as shown in FIG. That is, each of the bus bars 250 a and 250 b has a functional part similar to one of the conductive members 251 and 252 of the bus bar 250. However, each bus bar 250a, 250b is independently formed integrally with the case side plate 130 as one bus bar and is not connected to other bus bars.

When the connecting screw 162 is inserted into the through hole 271 of the bus bar 250a or 250b and fastened to the female screw portion 130a of the case side plate 130, the bus bars 250a and 250b are pressed against the end of the connection terminal 180 or 181 at the other end. . Accordingly, the bus bars 250a and 250b are connected to the connection terminals 180 and 181 respectively. In this state, the joining portions 162 of the bus bars 250a and 250b are joined to the secondary battery cell 140, respectively.
The bus bars 250, 250a, 250b and the secondary battery cell 140 are joined by, for example, arc welding such as TIG (Titan Inert Gas) welding or gas shielded arc welding.
The through holes 261 provided in each bus bar 250, 250 a, 250 b are for guiding the gas to the gas discharge passage 138 when the gas is ejected from the secondary battery cell 140.

Each bus bar 250, 250 a, 250 b is fastened to the female screw portion 130 a by a connecting screw 162, whereby each bus bar 250, 250 a, 250 b is connected to the female screw of the connection pad 800 a provided on the detection line 806 of the voltage detection conductor 805. Connected to. Therefore, the potential of each secondary battery cell 140 is supplied to the voltage sensor of the cell controller 310 via the bus bars 250, 250 a, 250 b, the connecting screw 162, and the detection line 806. The cell controller 310 detects the voltage of each secondary battery cell 140 from the potential input from each detection line 806.
The connection pad 800a provided on the detection line 806 is a normal connection wiring and is formed very thin. For this reason, the internal thread is not formed in the connection pad 800a, but it may be a simple through-hole, or the hole may be formed by fastening the connecting screw 162 while remaining solid.

With reference to FIG. 6, an example of a method for detecting individual voltages of secondary battery cells BC1 to BC16 will be described.
For example, the voltage of the secondary battery cell BC4 is detected as a potential difference between the potential output from the detection line 806 via the bus bar W2 and the potential output from the detection line 806 via the bus bar W9. The voltage of secondary battery cell BC5 is detected as a potential difference between the potential output from detection line 806 via bus bar W9 and the potential output from detection line 806 via bus bar W3. In this way, the voltages of the other secondary battery cells 140 are also detected by the cell controller 310, respectively.

(Replacement method of secondary battery cell)
Next, a method for replacing the secondary battery cell 140 will be described with reference to FIG.
As described above, the voltage of the secondary battery cell 140 housed in the power storage module 100 is monitored by the cell controller 310.
Therefore, the secondary battery cell 140 in which the battery voltage does not reach a predetermined voltage after charging the power storage module 100 in advance, or the secondary battery cell 140 that needs to be replaced earlier than the other secondary battery cells 140 is used. Check.

In step S1, the bolt 161 of the cover plate 160 attached to one of the case side plates 130 and 131 is removed. Although either side of the case side plates 130 and 131 may be used, here, a case where the bolt 161 of the cover plate 160 attached to the case side plate 130 is removed is illustrated.
Next, in step S <b> 2, the cover plate 160 and the O-ring 135 are removed from the case side plate 130.

Next, in step S3, the connecting screws 162 of the bus bars 250, 250a, 250b joined to the secondary battery cell 140 to be replaced are removed. There may be one or a plurality of secondary battery cells 140 to be replaced. However, all the bus bars 250, 250 a, 250 b joined to the secondary battery cell 140 to be replaced are attached to the case side plate 130. The fastening connecting screw 162 is removed.
In the case of the bus bar 250, the conductive members 251 and 252 are separated by removing the connecting screw 162, and the connecting portions 270 of the conductive members 251 and 252 are released from the case side plate 130. In the case of the bus bar 250a or 250b, the end of the bus bar 250a or 250b that is in contact with the connection terminals 180 and 181 is released from the case side plate 130 by removing the connecting screw 162.

Next, in step S4, the case body 110 is inverted and the case side plate 131 side is directed upward.
Next, the bolt 161 of the cover plate 160 attached to the case side plate 131 is removed in step S5.
Next, in step S <b> 6, the cover plate 160 and the O-ring 135 are removed from the case side plate 131.

Next, in step S7, the connecting screws 162 of all the bus bars 250 are removed. Thereby, on the case side plate 131 side, all the conductive members 251 and 252 constituting the bus bar 250 are separated, and each connecting portion 270 is released from the case side plate 131.
As is apparent with reference to FIGS. 5 and 6, the case side plate 131 is not provided with the connection terminals 180 and 181.

  Next, in step S8, the bolt 163 (see FIG. 5) attaching the case side plate 131 to the case main body 110 is removed. In FIG. 5, only the bolt 163 for attaching the case side plate 130 to the case main body 110 is illustrated, but the case side plate 131 is similarly attached to the case main body 110 by the bolt 163.

  Next, the case side plate 131 is removed from the case main body 110 in step S9. In each of the conductive members 251 and 252, the joint portion 262 is joined to the secondary battery cell 140, but since the connecting portion 270 side is free, the side plate through hole 132 of the case side plate 131 is inserted. Thus, the case side plate 130 can be removed. Although not shown, the case side plate 131 and the case main body 110 may be assembled via a seal member. In that case, the seal member is removed as necessary.

  Next, in step S10, the secondary battery cell 140 is replaced. By removing the connection screw 162 in step S3, the end of the bus bar 250 joined to the replacement secondary battery cell 140 or the end of the bus bar 250a, 250b that is in contact with the connection terminals 180, 181 is free. It has become. Therefore, the connecting portion 270 of the bus bar 250 or the bus bars 250a and 250b of the secondary battery cell 140 to be replaced is inserted through the side plate through hole 132 of the case side plate 130, and the secondary battery cell 140 to be replaced is taken out from the case body 110. Then, the new secondary battery cell 140 is accommodated in the case main body 110. Thereby, the secondary battery cell 140 is replaced with the case main body 110.

Thereafter, the above-described disassembly order may be reversed to assemble the battery container.
That is, the case side plate 131 is positioned and attached to the case main body 110 in step S11, and the bolt 163 is fastened to attach the case side plate 131 to the case main body 110 in step S12. In the case where the seal member is disposed between the case side plate 131 and the case main body 110, the bolt 163 is fastened with the seal member interposed between the two members.

  Next, in step S13, the connecting screw 162 is fastened to the female screw portion 130a of the case side plate 131, and all the conductive members 251 and 252 constituting the bus bar 250 are connected by the connecting portions 270 and attached to the case side plate 131. . Further, the bus bars 250a and 250b are attached to the case side plate 131 by the connecting screws 162, and the other end portions are pressed and connected to the connection terminals 180 and 181. By fastening the connecting screw 162 to the female screw portion 130a of the case side plate 131, the bus bars 250, 250a, 250b are connected to the connection pads 800a of the voltage detection conductor 805 via the connecting screws 162, respectively. That is, the secondary battery cells 140 are each connected to the voltage detection conductor 805.

  Next, in step S14, the joined portion 262 of the bus bars 250, 250a, 250b is joined to the replaced secondary battery cell 140 by arc welding or the like.

  Next, in step S15, the cover plate 160 and the O-ring 135 are attached to the case side plate 131. Next, in step S16, the case side plate 131 is attached to the case main body 110 with the bolt 161.

Next, in step S17, the case body 110 is inverted so that the case side plate 131 side is on the lower side and the case side plate 130 side is on the upper side.
Next, in step S18, the connecting screw 162 removed in step S3 is fastened. That is, in the case of the bus bar 250, the connecting screw 162 is fastened to the female screw portion 130 a of the case side plate 131, the conductive members 251 and 252 are connected by the connecting portion 270, and the bus bar 250 is attached to the case side plate 130. Further, in the case of the bus bars 250a and 250b, the bus bars 250a and 250b are attached to the case side plate 131 by the connecting screws 162, and the other end portions are press-contacted to the connection terminals 180 and 181 to be connected. By fastening the connecting screw 162 to the female screw portion 130 a of the case side plate 130, the bus bars 250, 250 a, 250 b are connected to the connection pad 800 a of the voltage detection conductor 805 through the connecting screw 162.

  Next, in step S19, the joined portions 262 of the bus bars 250, 250a, 250b are joined to the replaced secondary battery cell 140 by arc welding or the like. Thereby, all 16 secondary battery cells 140 are connected in series, and the positive electrode terminal 140a and the negative electrode terminal 140b of each secondary battery cell 140 are connected to the voltage detection conductor 805.

Next, in step S20, the cover plate 160 and the O-ring 135 are attached to the case side plate 130, and in step S21, the assembly of the secondary battery cell 140 is completed by attaching it to the case side plate 130 with the bolt 161.
Thereafter, the individual battery voltages of all the secondary battery cells 140 including the replaced secondary battery cell 140 and the total voltage of the 16 secondary battery cells 140 are detected by the cell controller 310 as necessary. The detection result is confirmed by a display device or the like.

  In addition, in the replacement method of the secondary battery cell 140 described above, the method is exemplified by the method of disassembling from the case side plate 130 side. In addition, on the case side plate 130 side or 131 side to be disassembled first, the method is illustrated by a method of removing only the connecting screws 162 of the conductive members 251 and 252 of the bus bar 250 joined to the secondary battery cell 140 to be replaced. However, on the case side plate 130 side or 131 side to be disassembled first, the connection screws 162 of the conductive members 251 and 252 of all the bus bars 250 joined to the secondary battery cell 140 may be removed. In this method, when the case side plate 130 or 131 opposite to the case body 110 is removed, only the connecting screws 162 of the conductive members 251 and 252 of the bus bar 250 joined to the secondary battery cell 140 to be replaced are removed. You can do it.

--Embodiment 2-
FIG. 11 is an exploded perspective view of the bus bar 250A according to the second embodiment of the present invention.
The bus bar 250A shown as the second embodiment is different from the bus bar 250 shown in the first embodiment in that the through-hole 271 formed in the connecting portion 270 of each of the conductive members 251 and 252 shown in the first embodiment is notched 272. This is the point.
The notch 272 is formed in a U shape in a plan view opened to the outside from the distal end side portion of the connecting portion 270. The bus bar 250A is formed as follows.

First, the connecting portions 270 of the conductive members 251 and 252 are stacked with the notches 272 being concentric. In this way, a substantially circular through hole is formed by the semicircular portion of the notch 272 of each conductive member 251, 252. Therefore, the coupling screw 162 is inserted into the through hole and fastened to the female screw portion 130a of the case side plate 130 and the female screw of the connection pad 800a of the voltage detection conductor 805, as in the first embodiment.
As a modification, one of the cutouts 272 of the conductive members 251 and 252 may be a through hole 271 as illustrated in the first embodiment.
The other configuration of the bus bar 250A is the same as that of the bus bar 250 of the first embodiment, and the corresponding components are denoted by the same reference numerals and description thereof is omitted.

--Embodiment 3--
FIG. 12 is an exploded perspective view of the bus bar 250B according to the third embodiment of the present invention.
The bus bar 250 </ b> B shown as the third embodiment includes conductive members 251 a and 252 a and a connecting member (intermediate connection member) 253.
In the conductive members 251a and 252a, through holes 271a and 271b are formed in the connecting portions 270a and 270b, respectively. The connecting member 253 is formed with a through hole 253a corresponding to the through hole 271a and a through hole 253b corresponding to the through hole 271b. The distal end side portion of the connecting portion 270a of the conductive member 251a and the distal end side portion of the connecting portion 270b of the conductive member 252a are arranged slightly apart. At this time, the joint portions 260 of the conductive members 251a and 252a are positioned in the side plate through holes 132 of the case side plates 130 and 131. Although not shown, one connecting screw is inserted through the through hole 253a of the connecting member 253 and the through hole 271a of the connecting portion 270a and fastened to the case side plates 130 and 131. Further, another connecting screw is inserted through the through hole 253b of the connecting member 253 and the through hole 271b of the connecting portion 270b and fastened to the case side plates 130 and 131.

Thus, the conductive member 251a and the conductive member 252a are integrated as the bus bar 250B and attached to the case side plates 130 and 131.
Similarly to the bus bar 250 of the first embodiment, one or both of the coupling screws may be connected to the connection pad 800a of the voltage detection conductor 805 when fastened to the female screw portion 130a.
In the bus bar 250B shown in the third embodiment, the connecting portion 270a of the conductive member 251a and the connecting portion 270b of the conductive member 252a do not overlap each other, and the length from each welded portion 262 is short. Therefore, when the secondary battery cell 140 to be replaced is taken out from the case main body 110 in step S10 of the battery replacement processing flow shown in FIG. 10, the connecting portions 270a and 270b of the bus bar 250B are inserted into the side plate through holes 132 of the case side plate 130. Work becomes easier.

As a modified example of the third embodiment, one or both of the through holes 271a and 271b formed in the connecting portions 270a and 270b may be configured as notches 272 illustrated in FIG. One or both of the through holes 253a and 253b formed in the connecting member 253 may be cut out.
The other configurations relating to the bus bar 250A are the same as those of the bus bar 250 of the first embodiment, and the corresponding components are denoted by the same reference numerals and description thereof is omitted.

--Embodiment 4--
13 to 15 relate to a fourth embodiment of the present invention, FIG. 13 is a perspective view of a bus bar, and FIG. 14 is a plan view of a voltage detection conductor. FIG. 15 is a view for explaining a method of attaching the bus bar according to the fourth embodiment. FIG. 15 (A) shows the first step, and FIG. 15 (B) shows the step following FIG. 15 (A). It is a perspective view for doing.
In FIG. 13, the bus bar 250C shown in the fourth embodiment is formed by extending the connecting member 253 of the bus bar 250B shown in FIG. 12 by extending the detection line 806 of the voltage detection conductor 805 shown in FIG. Is.

FIG. 14 is an enlarged plan view of a part of the right side of the voltage detection conductor 805 shown in FIG.
Each detection line 806a is extended from the resin part 807, and the rectangular connection part 808 is formed in the front-end | tip part. In each connecting portion 808, through holes 808a and 808b corresponding to the through holes 271a and 271b of the conductive members 251a and 252a are formed. In order to configure the bus bar 250c, as shown in FIG. 16A, first, the detection line 806a is bent approximately 90 ° in the vicinity of the base of the connecting portion 808, and the connecting portion 808 is paired with two pairs of two. At the boundary portion of the side plate through-hole 132 of the secondary battery cell 140, it is made substantially parallel to the upper surfaces of the case side plates 130 and 131.

  Next, as illustrated in FIG. 15B, the conductive member 251a and the conductive member 252a are electrically connected to the connection portion 270a of the conductive member 251a between the connection portion 808 and the upper surfaces of the case side plates 130 and 131. The distal end side portion of the connecting portion 270b of the member 252a is disposed slightly apart. At this time, the joint portions 260 of the conductive members 251a and 252a are positioned in the side plate through holes 132 of the case side plates 130 and 131, respectively. Then, the connecting screw 162a is inserted through the through hole 808a provided in the connecting portion 808 of the detection line 806a and the through hole 271a of the connecting portion 270a, and fastened to the case side plates 130 and 131. Further, the connecting screw 162b is inserted through the through hole 808b of the connecting portion 808 of the detection line 806a and the through hole 271b of the connecting portion 270b, and fastened to the case side plates 130 and 131.

In the fourth embodiment, the connecting portion 808 of the bus bar 250C is formed by extending the detection line 806a of the voltage detection conductor 805. Therefore, it is not necessary to form the connection pad 800a for connecting the coupling screws 162a and 162b on the detection line 806a of the voltage detection conductor 805.
Other configurations of the fourth embodiment are the same as those of the third embodiment, and the corresponding components are denoted by the same reference numerals and description thereof is omitted.

In the fourth embodiment, the connecting portion 808 formed by extending the detection line 806a is very thin, and the through hole 808a is a so-called fool hole that loosely fits the connecting screws 162a and 162b. be able to.
Further, the connecting portion 808 formed by extending the detection line 806a is illustrated as a structure arranged on the upper portions of the conductive members 251a and 252a and connected by the connecting screws 162a and 162b. However, the connecting portion 808 may be arranged below the conductive members 251a and 252a or connected between the conductive members 251a and 252a.

--Embodiment 5--
FIG. 16 is a perspective view of a bus bar 250D showing Embodiment 5 of the present invention.
A bus bar 250D in FIG. 16 includes the bus bar 250 shown in FIG. 8 as the first embodiment and a connection portion 808 extending from the detection line 806b of the voltage detection conductor 805 shown in the fourth embodiment. The connecting portion 808 is formed with a U-shaped notch 808c in plan view.

In order to configure the bus bar 250D, as shown in FIG. 8, the through holes 271 of the conductive members 251 and 252 are concentric, the connecting portions 270 of the conductive members 251 and 252 are overlapped, and on the connecting portion 270, The connecting portion 808 of the voltage detection conductor 805 is overlapped. The connection portion 808 of the voltage detection conductor 805 bends the detection line 806b at the base portion by about 90 ° as necessary. In this state, the connecting screw 162 is inserted into the notch 808 c of the connecting portion 808 of the voltage detection conductor 805 and the through hole 271 of the conductive members 251 and 252 and fastened to the female screw portion of the case side plate 130.
In the fifth embodiment, the connecting portion 808 of the bus bar 250D is formed by extending the detection line 806b of the voltage detection conductor 805. Therefore, it is not necessary to form the connection pad 800a for connecting the coupling screws 162a and 162b on the detection line 806b of the voltage detection conductor 805.
Other configurations of the fifth embodiment are the same as those of the first embodiment, and the corresponding components are denoted by the same reference numerals and description thereof is omitted.

[Effect of the embodiment]
As described above, in each embodiment of the present invention, the bus bars 250 and 250A to 250D that connect a pair of adjacent secondary battery cells 140 have at least one end of the positive terminal 140a or the negative terminal 140b of the secondary battery cell 140. A pair of conductive members 251 (251a) and 252 (252a) joined to each other, and the other ends of the conductive members 251 and 252 are fastened to the other conductive members 252 and 251 by connecting screws 162, 162a, and 162b. Connected by. Accordingly, the secondary battery cells 140 are individually removed from the case body 110 by removing the connecting screws 162, 162 a, 162 b and freeing the other ends of the conductive members 251, 252. It is possible to exchange it.
Therefore, the increase in the number of parts can be suppressed, and the number of processes can be reduced because the positive and negative terminals 140a and 140b, the bus bar, and the bus bars 250 and 250A to 250D can be welded only once.

  In the above embodiment, the positive and negative terminals 140a and 140b of the secondary battery cells 140 are connected via the bus bars 250 and 250A to 250D by the connecting screws 162 that connect the conductive members 251 (251a) and 252 (252a). Was connected to the voltage detection conductor 805. For this reason, the process of welding the voltage detection conductor 805 to the bus bars 250, 250A to 250D can be omitted, and each secondary battery cell 140 can be connected to the voltage detection circuit.

  According to the electricity storage modules 100a and 100b according to the above embodiment, the following effects can be obtained in addition to the effects described above. (1) The power storage modules 100a and 100b include a pair of resin-made case side plates 130 and 131 that sandwich and support a plurality of secondary battery cells 140 accommodated in the case main body 110 from both sides. As shown in FIG. 7, the voltage detection conductor 805 is formed in a predetermined shape and integrated with the case side plates 130 and 131. This eliminates the need for a space for manually installing the voltage detection lead wires to the case side plates 130 and 131 and a complicated manufacturing process, and allows the power storage module 100 to be manufactured efficiently. In particular, the voltage detection conductor 805 can be easily installed on the power storage module 100 that is required to be downsized.

(2) The plurality of bus bars 250 are attached to the case side plates 130 and 131 from the outside of the case main body 110 in order to connect the plurality of secondary battery cells 140. Thereby, connection with the bus-bar 250 and each secondary battery cell 140 can be performed easily.

(3) The connection pad 800a of the voltage detection conductor 805 is connected to the plurality of bus bars 250, and the other end of the voltage detection conductor 805 has a current interrupt device (current interrupter) that interrupts the current from the secondary battery cell 140. ) 811 is provided. The current interrupting unit 811 protects the product by cutting off the current from the secondary battery cell by fusing the fuse wire when the control device 900 or the connection wiring 800 is abnormal.
By providing the current interrupting unit 811 at the other end of the voltage detection conductor 805, for example, when a short circuit occurs in the connection wiring 800, the current interrupting unit 811 interrupts the current at the other end of the voltage detecting conductor 805. It will be. Thereby, the whole electrical storage module 100 can be protected. In this case, the power storage module 100 can be reused by replacing the connection wiring 800 and the current cutoff unit 811. In addition, since the voltage detection conductor 805 is formed into a predetermined shape and is integrated with the case side plates 130 and 131, the voltage detection conductor 805 itself is not substantially short-circuited.

(4) The voltage detection conductor 805 is integrated with the case side plates 130 and 131 by being insert-molded into the resin case side plates 130 and 131 while being maintained in a predetermined shape by the resin portion 807. Specifically, the voltage detection conductor 805 is fixed by the resin portion 807 so as to maintain the molded shape, and the subunit is manufactured, and the subunit is insert-molded to manufacture the case side plates 130 and 131. By creating the subunit, the shape of the voltage detection conductor 805 can be reliably maintained, and the detection lines 806 of the voltage detection conductor 805 can be prevented from accidentally contacting each other in the manufacturing process.

(5) The case side plates 130 and 131 are formed with side plate through holes 132 at positions corresponding to the plurality of secondary battery cells 140, and each of the secondary battery cells 140 has the positive and negative terminals 140 a and 140 b provided on the case side plate 130. , 131 are adhered to each other with an adhesive. As a result, the space inside the case body 110 and the outside space can be more reliably separated, and the reliability is improved. In addition, the connection state between the case side plates 130 and 131 and the secondary battery cell 140 can be maintained while absorbing an external force applied to the power storage module 100, for example, vibration or the like by the adhesive.

(6) The case main body 110 further includes a metal cover plate 160 provided so as to cover the outside of the pair of case side plates 130 and 131, and the case side plates 130 and 131 include the cover plate 160 and the bus bar 250. The internal thread part 130a for collision prevention and the rib 136 for preventing this contact are included. For example, when an external force is applied to the cover plate 160 and the case plate 110 is deformed to the inside of the case main body 110, the cover plate 160 first contacts the female screw portion 130 a or the rib 136 protruding from the surface of the case side plates 130 and 131. Thereby, it can prevent that the iron cover board 160 and the bus-bar 250 contact, for example, and a short circuit generate | occur | produces. In addition, since the rib 136 surrounds the entire periphery of the bus bar 250 except for the vicinity of the connection pad 800a, it can withstand various external forces.

(7) The power storage device 1000 detects the voltages of the plurality of secondary battery cells 140 connected to the power storage module 100 and the voltage detection conductor 805, and controls the power storage amount of the plurality of secondary battery cells 140. With. As described above, since the power storage module 100 can be manufactured without performing complicated wiring work of voltage detection lines, the entire power storage device 1000 can be manufactured efficiently.

(Other variations)
In each of the above embodiments, the secondary battery cells 140 accommodated in the case main body 110 are arranged in one row, in other words, each secondary battery cell 140 has a positive electrode terminal 140a and a negative electrode terminal 140b. Each of the cases is illustrated as a structure exposed from the side plate through holes 132 of the case side plates 130 and 131 disposed on the opposite side surfaces of the case main body 110. However, the secondary battery cells 140 may be arranged in a plurality of rows in the case body 110. In this case, a plurality of secondary battery cells 140 are arranged in a row corresponding to each side plate through-hole 132 of the case body 110, and the secondary battery cells 140 are directly connected to each other. The positive and negative terminals 140a and 140b of the secondary battery cell can be connected or can be connected via a connecting member.

The storage structure of the secondary battery cell 140 is not limited to the case structure using the case main body 110, the case side plates 130 and 131, and the cover plate 160.
Further, the conductive members 251 and 252 or the connecting member 253 constituting the bus bars 250 and 250A to 250D are not limited to copper or copper alloy, but two kinds of aluminum, nickel, stainless steel, iron, or these metal materials It is good also as a clad material consisting of the above.

As a connection means for connecting the conductive members 251 (251a) and 252 (252a), a fastening member such as a bolt or a caulking pin can be used in addition to a screw.
Alternatively, the conductive members 251 and 252 may be stacked with a compression leaf spring, or may be connected with a connecting member having an engaging portion that engages with each of the conductive members 251 and 252.

In the said embodiment, although the cylindrical lithium ion secondary battery cell was illustrated as the secondary battery cell 140, this invention is not limited to this. In addition to the lithium ion battery, the present invention is also applied to other batteries such as a nickel metal hydride battery.
Moreover, it can apply not only to a secondary battery cell but to capacitors, such as cylindrical lithium ion.

  The power storage device 1000 according to the above embodiment is used in a power supply device for a vehicle such as another electric vehicle, for example, a railway vehicle such as a hybrid train, a shared vehicle such as a bus, a cargo vehicle such as a truck, and an industrial vehicle such as a battery-type forklift truck. You can also

  The power storage device 1000 according to the above embodiment may be applied to a power storage device that constitutes a power supply device other than an electric vehicle, such as an uninterruptible power supply device used in a computer system or a server system, a power supply device used in a private power generation facility I do not care.

  In addition, the power storage module of the present invention can be variously modified and configured within the scope of the present invention. In short, the bus bars 250, 250A to connect a pair of adjacent secondary battery cells 140 are the main points. 250D is composed of a pair of conductive members 251 (251a) and 252 (252a) having at least one end joined to the positive electrode terminal 140a or the negative electrode terminal 140b of the secondary battery cell 140, and the other ends of the respective conductive members 251 and 252. May be anything that can be attached to and detached from the other conductive members 252 and 251.

100a, 100b Power storage module 110 Case body 130, 131 Case side plate 130a Female thread part 132 Side plate through hole (through hole)
140 Secondary battery cell 140a Positive electrode terminal 140b Negative electrode terminal 160 Cover plate 162, 162a, 162b Connection screw 250, 250a, 250b Bus bar 250A-250D Bus bar 251, 251a Conductive member 252, 252a Conductive member 253 Connecting member (intermediate connecting member)
260 Joint (one end)
262 Joint part 270 Connecting part (other end)
271 Through-hole 272 Notch 805 Voltage detection conductor 806, 806a, 806b Detection line 807 Resin part 808 Connection part 900 Control apparatus 1000 Power storage apparatus

Claims (9)

A case body having openings on both side surfaces;
A plurality of secondary battery cells accommodated in the case body, with positive and negative terminals facing the opening of the case body,
A pair of case side plates covering the openings of the case body in which the secondary battery cells are housed, and having through holes exposing the positive and negative terminals of the secondary battery cells;
A bus bar that is joined to the positive electrode terminal or the negative electrode terminal of the secondary battery cell through the through hole of the case side plate and connects a pair of adjacent secondary battery cells;
The bus bar includes at least one end of a pair of conductive members joined to a positive terminal or a negative terminal of the secondary battery cell, and the other end of each conductive member is detachably connected to the other conductive member. A power storage module.   2. The power storage module according to claim 1, wherein each of the other ends of the pair of conductive members is provided with a through hole or a notch, and each of the conductive members is inserted through the through hole or the notch. An electricity storage module, which is fixed and connected by a fastening member.   The power storage module according to claim 1, wherein the bus bar further includes an intermediate connection member, and the pair of conductive members are connected to each other via the intermediate connection member. Power storage module.   4. The power storage module according to claim 3, wherein the intermediate connection member is provided with a through hole or a notch corresponding to a through hole or a notch provided at the other end of each of the conductive members. The electrical storage module, wherein the conductive member is fixedly connected by a fastening member inserted through the through hole or notch of each conductive member and the through hole or notch of the intermediate connection member.   5. The power storage module according to claim 1, further comprising a voltage detection wiring for the secondary battery cell, wherein the fastening member is connected to the wiring. Power storage module.   5. The power storage module according to claim 1, further comprising a voltage detection wiring for the secondary battery cell, wherein the wiring includes a connecting portion connected to the pair of conductive members. A power storage module comprising:   7. The power storage module according to claim 6, wherein the connecting portion is formed with a pair of through holes or notches corresponding to the through holes or notches provided at the other end of each of the conductive members. A power storage module characterized by the above.   The power storage module according to claim 6, wherein the other end of the pair of conductive members and the connecting portion are stacked and connected.   The power storage module according to any one of claims 5 to 8, wherein the voltage detection wiring of the secondary battery is integrally formed on the case side plate.

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