JP2012243515A - Power storage module and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a primary molding which fixes a connection conductor and a secondary molding which covers the primary molding difficult to be peeled by thermal shock.SOLUTION: A voltage detection conductor 805 is insert-molded to the case side plates 130, 131. The detection line 806 of the voltage detection conductor 805 is fixed by a resin 807 formed by a primary molding. The resin 807 has a plurality of joints 820. Each joint 820 has a fixing part 821 and a fusible part 822. When the resin 807, a primary molding part, is subjected to secondary molding, the edge 822a of the fusible part 822 is melted by the heat and injection pressure of a secondary molding material injected, and fused with the secondary molding material. Consequently, a primary molding material and the secondary molding material are bonded strongly.

Description

  The present invention relates to a power storage module including a battery container that houses a plurality of battery cells, and a method for manufacturing the same.

2. Description of the Related Art A power storage device is known in which battery cells such as secondary batteries are housed in a battery container in which electrical components such as a protection circuit are integrally formed with a resin mold.
An electric wire mold housing is known as a structure in which electrical components are integrated by a resin mold. As an example of this, the outer periphery of the shielded wire is covered with a primary molded resin portion having flexibility such as urethane, and the outer periphery of the primary molded resin portion is covered with a hard secondary molded resin portion such as PBT (polybutylene terephthalate). (For example, refer to Patent Document 1).

JP 2002-186129 A

  The structure disclosed in Patent Document 1 is not related to a power storage device. In the power storage device, it is necessary to form the primary molded resin portion and the secondary molded resin portion with a hard resin. When the primary molded resin part and the secondary molded resin part are in contact with each other only at the boundary surface of the molded resin part, the bonding strength is weak, and they peel off from the bonded surface under severe temperature and impact environments. There is a high possibility of end.

  The power storage module of the present invention is integrally formed with a case main body in which a plurality of power storage cells are stored, and electrode terminals of the power storage cells stored in the case main body, and a connection conductor for detecting the voltage of the power storage cells is integrally formed. The case side plate, the case side plate has a primary molded part in which at least a part of the connection conductor is integrally formed, and a secondary molded part formed so as to cover the primary molded part, and the primary molded part is A body portion covering the outer surface of the connecting conductor, a fixing portion formed in a protruding shape from the body portion and exposed to the outer surface of the secondary molding portion, and between the body portion and the exposed surface of the fixing portion. And a meltable part provided.

  Further, in the method for manufacturing a power storage module according to the present invention, the connection body for detecting the voltage of the power storage cell is integrally formed with the case body in which the plurality of power storage cells are housed, connected to the electrode terminal of the power storage cell. A method for manufacturing a power storage module to which a case side plate is attached, wherein the step of forming the case side plate is provided on a main body side that covers the connection conductor, a fixed portion protruding from the main body portion, and a main body portion side of the fixed portion. A step of forming a primary molded body having a meltable portion, and a step of molding a secondary molded body that covers the outer surface of the primary molded body in a state where the fixing portion of the primary molded body is fixed. .

  According to the present invention, the meltable part formed on the main body side of the primary molding part is melted by the secondary molding material, so that the bonding strength between the primary molding part and the secondary molding part can be improved. Moreover, since the secondary molding part is formed in a state where the fixing part of the primary molding part is fixed, the position of the connection conductor in the thickness direction of the secondary molding part can be reliably fixed at a required position.

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 top view which shows the structure of a voltage detection conductor. The top view which shows the state which incorporated the voltage detection conductor in the case side plate. Enlarged perspective view of the main part of the primary molded resin part FIG. 9 is a cross-sectional view of the primary molded resin portion illustrated in FIG. 8. The perspective view of the electrical storage module which has a case side plate by which the connection conductor was integrally shape | molded. The perspective view which shows the connection state of the derivation | leading-out part of the connection conductor integrally molded by the case side plate, and a bus bar. (A) is a plan view of a state in which a bus bar is mounted on the case side plate shown in FIG. 11, (b) is a cross-sectional view taken along line bb of FIG. 12 (a), and (c) is c of FIG. 12 (a). -C sectional drawing. The flowchart as one embodiment which shows the manufacture procedure of the electrical storage module of this invention.

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 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 a plurality of lithium ion battery cells (hereinafter referred to as “battery cells”) connected in series. First and second battery cell rows, which will be described later, are configured by a plurality of battery cells and a connection member that connects these battery cells in series. 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 battery cell, a command for adjusting the power storage amount of each 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 state of a plurality of lithium-in on battery cells according to a command from the battery controller 300, and includes a plurality of integrated circuits (ICs). The management and control of the state of a plurality of battery cells include measurement of the voltage of each battery cell, adjustment of the amount of electricity stored in each battery cell, and the like. That is, although not shown in FIG. 1, the cell controller 310 has a voltage sensor that measures the voltage of each battery cell. The voltage sensor includes an operational amplifier connected to the positive terminal and the negative terminal of each 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 battery cell. When each battery cell or the average value of the 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 battery cells, and performs state management and control on the corresponding battery cells.

A plurality of corresponding 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 plurality of 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 a voltage value charged in each 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 and negative terminals of each battery cell via the battery controller 300 like 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 power storage modules on the high potential side and the low potential side, respectively, and each of the power storage modules 100a and 100b is electrically connected in series and accommodates a plurality of battery cells. Has been. 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 battery cells 140 are accommodated in the battery container. The 16 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, it has the inlet flow path formation part 111, the outlet flow path formation part 118, the inlet side guide part 112 (refer FIG. 3), and the outlet side guide part 113 (refer FIG. 2, 5). The internal space of the case body 110 functions as a storage chamber in which a plurality of battery cells (storage cells) 140 are stored, and as a cooling passage through which a cooling medium (cooling air) for cooling the 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 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 (see FIG. 5) is a flat plate portion that forms the bottom surface of the case 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 (refer FIG. 3) is a plate-shaped part which forms one side of the side surface which opposes the longitudinal direction of the case main body 110. As shown in FIG. 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 battery cells 140 in the longitudinal direction, and a step corresponding to the amount of deviation is formed at the end portion on the inlet side 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 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 battery cell 140 is stored. The cover plate 160 is fixed to the case side plates 130 and 131 by fastening members 161 (see FIG. 4) such as bolts or rivets.

  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. . In the cover plate 160, a region including a portion corresponding to a side plate through hole 132 of case side plates 130 and 131 described later swells uniformly on the side opposite to the case side plate 130, that is, toward the outside of the case main body 110. 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 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 plurality of battery cells 140 are stored in alignment in a storage chamber formed inside the case body 110, and are sandwiched between the case side plates 130 and 131 from the short side direction, and are made of a material having good conductivity such as copper. Are electrically connected in series by joining with the bus bar 150 formed by the above.
The 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 is a battery can in which a nonaqueous electrolyte is injected. Components such as a power generation unit and a safety valve are housed inside. The positive electrode terminal 140a has an opening 140a1 at the center, and the pressure inside the battery container has become a predetermined pressure due to an abnormality such as overcharging immediately below the opening 140a1 of the positive electrode terminal 140a in the axial direction. A cleavage valve (not shown) that is sometimes cleaved is formed. The cleaving 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 by cleaving, and is a mist-like carbon dioxide containing gas generated inside the battery container, that is, a non-aqueous electrolyte. It functions as a decompression mechanism that ejects the system gas to the outside of the battery container.

  The negative electrode terminal 140b is a can bottom of the battery cell 140, and the cleavage valve 140b1 is also provided in the negative electrode terminal 140b which is the can bottom. The cleavage valve 140b1 is formed by forming a groove having a V-shaped cross section by pressing the can bottom of the battery cell 140. The cleavage valve 140b1 is cleaved when the internal pressure of the battery container becomes a predetermined pressure or higher due to an abnormality such as overcharge. Thereby, the gas generated inside the battery can can be ejected also from the negative electrode terminal side. The 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 battery cells 140 are arranged in alignment inside the case body 110. Specifically, the battery cell 140 is turned sideways, in other words, the axis of the battery cell 140 is arranged in parallel to the short side direction, and eight battery cells 140 are arranged in parallel on the upper side along the longitudinal direction. Thus, the first battery cell row 121 is configured. Similarly to the first battery cell row 121, eight 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, the battery cells 140 are arranged in eight rows in the longitudinal direction and two stages 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 battery cell 140 located closest to the cooling medium outlet 115 of the first battery cell row 121 is the second battery cell row 122. The first battery cell row 121 and the second battery cell row 122 are arranged at an intermediate position between the central axis of the battery cell 140 located closest to the cooling medium outlet 115 and the central axis of the battery cell 140 adjacent thereto. Are displaced in the longitudinal direction.

  The 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 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 arrangement order of the positive and negative terminals 140a and 140b of the 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 cell row. This is different from the arrangement order of the terminals of the battery cells 140 constituting 122.

That is, in the first battery cell row 121, the terminals of the battery cell 140 facing the case side plate 130 side are negative electrode terminal 140b, positive electrode terminal 140a, negative electrode terminal 140b, from the cooling medium inlet 114 side to the cooling medium outlet 115 side. ..., arranged in the order of the positive terminal 140a. On the other hand, in the second battery cell row 122, the terminals of the battery cells 140 facing the case side plate 130 are positive terminal 140a, negative terminal 140b, positive terminal 140a, from the cooling medium inlet 114 side to the cooling medium outlet 115 side. ..., arranged in the order of the negative terminal 140b.
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.

(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 (not shown) The terminal of the cable electrically connected to one end side of the SD switch 700 is connected. A terminal of a cable electrically connected to the other end side of the SD switch 700 is connected to the positive electrode side input / output terminal 183 (see FIG. 2) 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 184 (see FIG. 2) of the low potential storage module 100b. In FIG. 2, the sub-assembly 185 of the high-potential side power storage module 100a shows a state covered with a terminal cover, and the sub-assembly 185 of the low-potential side power storage module 100b shows a state where the terminal cover is removed. .

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 132 for accommodating the battery cells 140 are formed inside the side portion. Each side plate through-hole 132 is formed in a circular shape slightly smaller than the outer diameter of the 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 battery cells 140 are arranged so as to be closer to the cooling medium outlet 115 by the (1/2) pitch.

  When the 16 battery cells 140 are stored in the case main body 110, all the 16 side plate through holes 132 of the case side plate 130 are closed by the positive electrode terminal 140a or the negative electrode terminal 140b of the battery cell 140. Similarly, the 16 side plate through-holes 132 on the case side plate 131 side are also closed by one of the positive and negative terminals 140a and 140b of any one of the battery cells 140, although not shown. However, the terminal of the battery cell 140 in which the side plate through hole 132 of the case side plate 130 is closed and the side plate through hole 132 of the case side plate 131 corresponding to the side plate through hole 132 of the case side plate 130 are closed. As for the terminal, the positive electrode and the negative electrode are reversed.

  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. On the inner surface side of the case side plate 130, corresponding to each side plate through hole 132, a ring-shaped rib having a larger diameter than the through hole is formed. The ring-shaped rib serves as a guide member when the battery cell 140 is stored, and also functions as a holding member that holds the battery cell 140 after storage.

Each battery cell 140 held by a rib formed corresponding to each through hole of the case side plate 130 has a peripheral portion of the positive / negative electrode terminals 140a and 140b between the inside of the rib and the side plate through hole 132 described above. It is bonded to the case side plate 130 by an adhesive applied to a groove (not shown) formed on the case.
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 overcharging of the battery cell 140 or the like, the internal pressure in the battery cell 140 is increased, the cleavage valve is broken, and a mist-like gas (a liquid containing an electrolyte or the like is mixed with gas from the inside of the battery cell 140). Gas) may erupt or leak. 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 the side portion formed on the outer peripheral portion of the case side plate 130, and a seal member 135 is fitted in the groove 134. The seal member 135 is an annular seal member (for example, a rubber O-ring) having elasticity. A liquid gasket may be used for the seal member 135.

As illustrated in FIG. 5, between the case side plate 130 and the cover plate 160, a bus bar 150 that connects the positive terminal 140 a and the negative terminal 140 b of the adjacent battery cell 140 is disposed. Details of the bus bar 150 will be described later.
A plurality of fixed guides 130 a for arranging the bus bars 150 connected to the battery cells 140 are formed between the side plate through holes 132 in the outer wall surface 170 of the case side plate 130. The fixed guide 130 a is formed between a pair of positive terminal 140 a and negative terminal 140 b connected by the bus bar 150. By attaching the bus bar 150 to the fixed guide 130a, the joint portion of the bus bar 150 corresponds to a predetermined portion of the positive / negative electrode terminals 140a and 140b of the battery cell 140.
On the outer wall surface 170 side of the case side plate 130, a protrusion 136 is formed on the outer edge of the side plate through hole 132. The protruding portion 136 is formed in an approximately eight shape so as to connect the pair of side plate through holes 132 adjacent to the fixed guide 130a. The protrusion 136 and the fixed guide 130 a also have a function of preventing contact between the cover plate 160 made of a conductive material and the bus bar 150.

(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 provided at the bottom of 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 140a and 140b of the battery cell 140 to the outer wall surface 170 of the case body 110. Is formed. 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 formed integrally with the case side plate 130 by the same molding material as the case side plate 130, and is disposed on the cooling medium inlet 114 side on the upper surface of the case side plate 130.

(Voltage sensor connection wiring)
Each connection terminal 810 includes a current interrupting portion 811 (see FIGS. 6 and 7 described later), a connection wiring 800 extending from a voltage detection connector 912 (see FIGS. 2 and 3) of the control device 900, and a connection wiring 800 described later. The voltage detection conductor 805 to be connected is electrically connected via 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 melting when the control device 900 and the connection wiring 800 are abnormal to interrupt the current from each battery cell 140.

  The voltage detection conductor 805 is connected to the bus bar 150 that connects the battery cells 140 in series in order to detect the voltage of each of the plurality of 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. FIG. 6 is a plan view showing an example of the shape of the voltage detection conductor 805, and FIG. 7 is a plan view showing a state where the voltage detection conductor 805 shown in FIG.

  As shown in FIG. 6, the voltage detection conductor 805 has a long and thin rectangular detection line (connection conductor) 806 formed by pressing a thin metal plate such as copper, for example. The detection line 806 constituting the voltage detection conductor 805 has a tip end portion 800a of a predetermined side plate so that a part of the detection line 806 is exposed from a plurality of side plate through holes 132 formed in the case side plate 130. It is exposed to the inside of the through hole 132. That is, the detection line 806 is extended, and a part of the detection line 806 is led out from the side plate through hole 132 of the case side plate 130 (see FIG. 7). Each distal end portion 800a of the detection line 806 is bent toward the outside of the case side plate 130 and is welded to the bus bar 150 as described later. The other end of the voltage detection conductor 805 opposite to the tip 800 a is electrically connected to the connection terminal 810 via the current interrupting portion 811.

  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 battery cells 140 are connected in series via the bus bar 150, a potential difference is generated between the plurality of bus bars 150 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 (primary forming portion) 807 made of the same resin as the case side plate 130, for example. Specifically, the plurality of detection lines 806 are separated from each other by the resin portion 807, and each detection line 806 is fixed so as to maintain its shape.

  As shown in FIG. 6, the voltage detection conductor 805 fixed by the resin portion 807 is formed integrally with the case side plate 130 by, for example, insert molding with a resin constituting the case side plate 130. Since the detection lines 806 are fixed separately from each other, when the voltage detection conductor 805 is integrated with the case side plate 130, the detection line 806 is not substantially short-circuited. However, in order to further improve the reliability with respect to the short circuit between the detection lines 806, the distance between the detection lines 806 is set to 2 to 2.5 times or more of the insulation creepage distance required in this system. Thereby, it is possible to supply the case side plate 130 with high reliability. Also, the greater the distance, the more effective the contaminated environment.

4 and 5, 180 and 181 are respectively housed in the battery container of the power storage module 100 and are connected to both ends of 16 battery cells 140 connected in series, in other words, batteries having the highest potential and the lowest potential. It is a connection terminal connected to the positive terminal 140a and the negative terminal 140b of the cell 140.
The connection terminals 180 and 181 respectively have connection portions 180a and 181a and bus bars 150a and 150b (see FIG. 5), and are integrally formed on the case side plate 130 by insert molding.

(Forming the case side plate)
The voltage detection conductor 805 is integrally formed with the case side plate 130.
As described above, the voltage detection conductor 805 is fixed to the resin portion 807 by the primary forming of the detection line 806 having the tip portion 800a led out to the side plate through hole 132.
The resin portion 807 has a plurality of joint portions 820 as shown in FIG.
8 is an enlarged perspective view of a region A around the joint 820 of the voltage detection conductor 805 in FIG. 6, and FIG. 9 is a cross-sectional view thereof.

The resin portion 807 is made of, for example, PBT (polybutylene terephthalate). The resin portion 807 includes a main body portion 808 that covers the outer periphery of a long and thin rectangular wire-like detection line (connection conductor) 806, and a pair of joint portions 820 that are formed to protrude from the main body portion 808 to the upper and lower surfaces of the detection line 806. Have The pair of joint portions 820 are formed at a plurality of locations on the main body portion 808 of the resin portion 807.
Each joint portion 820 includes a columnar fixed portion 821 having an upper surface 821a, and a meltable portion 822 provided on the main body portion 808 side of the fixed portion 821. The meltable portion 822 has a cylindrical shape with a diameter larger than that of the fixed portion 821 and is formed coaxially with the fixed portion 821. The meltable part 822 is formed to be thinner and thinner than the height of the fixed part 821. The peripheral edge portion of the upper surface of the meltable portion 822 is a corner portion 822a having a corner, and can be melted by a molten secondary molding material injected at the time of secondary molding, which will be described later.

A method for forming the case side plate 130 will be described.
A voltage detection conductor 805 illustrated in FIG. 6 in which the detection line 806 is insert-molded in the resin portion 807 by primary molding is prepared in advance. In the resin portion 807, joint portions 820 having a fixing portion 821 and a meltable portion 822 are formed at a plurality of locations.
Next, the voltage detection conductor 805 is accommodated in the secondary molding die, and the lower die and the upper die are closed.
At this time, the upper surface 821a of the fixing portion 821 of the joint portion 820 on the upper side of the main body portion 808 is an upper die, and the upper surface (lower surface in FIG. 9) 821a of the fixing portion 821 of the joint portion 820 on the lower side of the main body portion 808 Pressed by.

For this reason, the position in the height (thickness) direction of the detection line 806 insert-molded in the resin portion 807 is reliably fixed at a predetermined position.
In this state, secondary molding is performed.
The secondary molding material that forms the case side plate 130 is preferably the same material as the primary molding material, for example, PBT.
The resin molding temperature in the secondary molding is the same as or slightly higher than the melting temperature of the primary molding material forming the resin portion 807.

The secondary molding material constitutes the secondary molding portion 130 'shown in FIG. When the secondary molding material is injected into the secondary molding die, the meltable portion 822 of the resin portion 807 formed of the primary molding material is melted by heat and injection pressure. In particular, the edge portion 822a at the peripheral edge of the upper surface of the meltable portion 822 is melted. The molten primary molding material fuses with the secondary molding material. For this reason, after that, by cooling the secondary molding material, the resin part 807 which is the primary molding part is firmly joined.

In the above, even when the secondary molding material is injected, since the resin portion 807 is much lower than the melting temperature, the surfaces of the main body portion 808 and the fixing portion 821 of the resin portion 807 are not melted so much and primary molding is performed. Fusion of the material and the secondary molding material is difficult to perform, and there may be a boundary surface that is separated without being joined.
As described above, the mist-like gas ejected from the battery cell 140 due to overcharge / discharge flows into the space between the case side plate 130 and the cover plate 160. When the boundary surface between the resin portion 807 and the secondary molded portion 130 ′ is separated, the mist-like gas flows into the case side plate 130 from the boundary portion between the resin portion 807 and the secondary molded portion 130 ′. Since the inside of the case side plate is a flow path for the cooling medium, mist-like gas enters the power storage device 1000.
However, in one embodiment of the present invention, an edge portion 822 a of the meltable portion 822 is formed between the fixing portion 821 and the main body portion 808. The edge portion 822a is formed in a circular shape, and is formed in a closed planar shape that is not exposed to the outside of the secondary molded portion 130 ′.
Therefore, even if the mist-like gas flows into the boundary portion between the fixed portion 821 and the secondary molding portion 130 ′, the mist-like gas is blocked by the edge portion 822a where the primary molding material and the secondary molding material are fused. It is possible to prevent inflow into the side plate 130.

As the secondary molding material, a material having a melting temperature higher than that of the primary molding material can be used. However, if the linear expansion coefficients of the secondary molding material and the primary molding material are different, there is a high possibility that both materials will be peeled off at the melted part due to the difference in the linear expansion coefficient when used in an environment where the thermal shock is severe.
Therefore, as the primary and secondary molding materials, for example, when the same material is used or different materials are used, it is desirable to use materials having the same linear expansion coefficient.

(Bus bar and battery cell)
FIG. 10 shows a perspective view of the power storage module 100 with the bus bar 150 attached to the case side plate 130.
The bus bar 150 is a metal, for example, copper plate-like member that electrically connects the battery cells 140, and is configured separately from the case side plate 130. However, as described above, the connection terminals 180 and 181 having the bus bars 150a and 150b (see FIG. 5) are formed integrally with the case side plate 130, respectively.

  The bus bar 150 includes a central portion 156 extending in a strip shape and terminal portions 157 located on both ends of the central portion 156. The central portion 156 and the terminal portion 157 are continuous via the bent portion 158, respectively. That is, the bus bar 150 is bent and formed in a step shape. Each terminal part 157 of the bus bar 150 has a through-hole 151, an electrode joint 152 welded to the positive and negative terminals 140 a and 140 b of the battery cell 140, and a wiring joint welded to the tip 800 a of the voltage detection conductor 805. 154 is formed.

  The through-hole 151 is provided so that when the gas is ejected from the battery cell 140 as described above, the ejected gas passes. In the central portion 156 of the bus bar 150, two positioning holes 155 for inserting the fixed guides 130a provided in the case side plate 130 are formed.

FIG. 11 is a perspective view showing a connection state between the lead portion of the connection conductor formed integrally with the case side plate and the bus bar, and FIG. 12A is a state in which the bus bar is attached to the case side plate shown in FIG. 12B is a cross-sectional view taken along the line bb of FIG. 12A, and FIG. 12C is a cross-sectional view taken along the line cc of FIG. 12A.
The bus bar 150 is attached to the case side plate 130 by fitting the two positioning holes 155 of the central portion 156 with the two fixed guides 130 a provided in the case side plate 130. When the bus bar 150 is attached to the case side plate 130, both terminal portions 157 of the bus bar 150 enter the side plate through hole 132 and come into contact with the terminal surface of the battery cell 140. In addition, the wiring joint portion 154 of the bus bar 150 is in contact with the tip end portion 800 a of the voltage detection conductor 805 exposed from the side plate through hole 132 formed in the case side plate 130. The pair of positive electrode terminal 140a and negative electrode terminal 140b welded by the bus bar 150 are at the same potential. For this reason, one tip 800a is drawn out with respect to the pair of positive and negative terminals 140a and 140b having the same potential. Accordingly, as shown in FIGS. 6 and 7, the tip end portion 800 a is exposed from only one of the pair of side plate through holes 132 and is not exposed from the other side plate through hole 132.

  The bus bar 150 is joined to the positive and negative terminals 140 a and 140 b of the battery cell 140 at the electrode joint 152 provided on both terminal parts 157. Specifically, the welding torch is aligned with the electrode joint 152, and the electrode joint 152 and the positive and negative terminals 140a and 140b of the battery cell 140 are joined by arc welding. Examples of arc welding include TIG (Titan Inert Gas) welding and gas shielded arc welding.

  Arc welding melts and joins a base metal and a filler metal with high heat, and generates super-high heat during welding. The heat at the time of welding is conducted to the periphery of the welded portion, and becomes high enough to melt the periphery. In particular, when the vicinity of the welded portion has a rectangular shape with corners or a rectangular through hole, heat concentrates on the corners and is easily melted. Further, as described above, since the through-hole 151 functions as a gas outlet when gas is ejected from the battery cell 140, it is necessary to avoid that the terminal portion 157 is melted and the opening is closed.

Therefore, in the present embodiment, as shown in FIGS. 11 and 12, rising portions 159 are provided on the outer side edges of the respective terminal portions 157 of the bus bar 150. The rising portion 159 is formed at a position corresponding to the vicinity of the center portion of the side plate through hole 132 of the case side plate 130.
By providing the rising portion 159 on the bus bar 150, the volume of the bus bar 150 is increased, and there is an effect of increasing heat dissipation during welding. This will be described below.

The terminal portion 157 of the bus bar 150 is shaped to fit within the circular side plate through hole 132 of the case side plate 130. For this reason, the width | variety of the terminal part 157 needs to make it smaller than the width | variety of the site | part of a corresponding circular through-hole in any site | part. Therefore, when the terminal portion 157 has a flat plate shape, the width is smaller than the diameter of the side plate through hole 132 in the region beyond the center portion of the side plate through hole 132.
On the other hand, in the embodiment of the present invention, as shown in FIG. 11, each terminal portion 157 of the bus bar 150 has a rising portion 159 at a position corresponding to the vicinity of the center portion of the side plate through hole 132 of the case side plate 130. Is provided. For this reason, the rising portion 159 can have the same width from the root to the tip of the rising portion 159 without being restricted by the shape of the side plate through-hole 132. That is, by providing the rising portion 159, the area of the terminal portion 157 can be made larger than when the rising portion 159 is not provided, and as a result, the volume of the bus bar 150 is increased to increase the heat dissipation during welding. Is possible.

  Moreover, in order to make it difficult to receive the influence of the heat which generate | occur | produces at the time of welding, it has comprised so that the through-hole 151 may be kept away from the electrode junction part 152 as much as possible. Specifically, the through hole 151 has an elliptical shape. The elliptical through hole 151 is arranged at an intermediate position between the two electrode joints 152 provided in each terminal portion 157. Each terminal portion 157 is formed with two electrode joint portions 152 that are joined to the positive electrode terminal 140a and the negative electrode terminal 140b. Therefore, one bus bar 150 has four electrode joints 152. The electrode bonding portion 152 is configured as a circular convex portion protruding toward the battery cell 140 side.

  As described above, the rising portions 159 are provided at the respective terminal portions 157 of the bus bar 150 to enhance the heat dissipation effect, and the through holes 151 are elliptical so that the edges of the through holes 151 are hardly melted. For this reason, high reliability is ensured with respect to heat generated during welding of the bus bar 150 and the battery cell 140.

  As illustrated in FIG. 12, the electrode bonding portion 152 is a convex portion with respect to the battery cell 140 and has a circular shape. Heat at the time of welding is conducted from the electrode joint portion 152 of the bus bar 150 to the positive and negative terminals 140a and 140b of the battery cell 140, and the joint portions of both members are melted to join. For this reason, the electrode joint portion 152 of the bus bar 150 has a function as a welding starting point during welding. For this reason, the size of the circular diameter is determined in consideration of the variation in the torch position of the welding equipment and the variation due to the combination of each component constituting the power storage device 1000. The circle has the same tolerance for variations in any direction, and the diameter of the circle is large enough to ensure the minimum area for the required weld strength, ensuring stable high quality in any case. The power storage device 1000 can be obtained.

As described above, the connection terminals 180 and 181 have bus bars 150a and 150b (see FIG. 5), respectively.
Each of the connection terminals 180 and 181 has a shape obtained by cutting the bus bar 150 at the central portion 156, and has a structure similar to that of the terminal portion 157 on one side of the bus bar 150.
That is, each bus bar 150a, 150b has a terminal portion 157 in which a through hole 151, a wiring joint portion 154, and two electrode joint portions 152 are formed.
In this case, the connection terminals 180 and 181 are arranged in a direction rotated by 90 degrees with respect to the bus bar 150, and are integrated with the case side plate 130 in a state where the connection portions 180 a and 181 a protrude to the outside above the case side plate 130, respectively. Molded.
As shown in FIG. 5, the front end portion 800 b connected to the positive electrode terminal 140 a of the battery cell 140 having the highest potential and the front end portion 800 c connected to the negative electrode terminal 140 b having the lowest potential are exposed from the side plate through hole 132. .
And the front-end | tip parts 800b and 800c are welded to the wiring junction part 154 of the bus-bars 150a and 150b, respectively. Since the functions of the through-hole 151, the wiring joint 154, and the two electrode joints 152 of each bus bar 150a, 150b are the same as those of the bus bar 150, the description thereof is omitted here.
The welding of the bus bars 150 a and 150 b of the connection terminals 180 and 181 and the positive terminals 140 a and 140 b of the battery cell 140 is performed in the same manner as the welding of the bus bar 150.

In the power storage device 1000 illustrated in FIGS. 2 and 3, the control device 900 is placed on the power storage module 100. Specifically, the control device 900 is an electronic circuit device placed over the high-potential-side power storage module 100a and the low-potential-side power storage module 100b, and is housed in the housing 910 and the housing 910. A single circuit board.
The casing 910 is a flat rectangular parallelepiped metal box, and is fixed to a high potential side power storage module 100a and a low potential side power storage module 100b by a fixing means such as a bolt or a screw. Thus, the high-potential side power storage module 100a and the low-potential side power storage module 100b are fixed by connecting the ends in the short direction to each other by the control device 900. That is, since the control device 900 also functions as a support, the strength of the power storage module 100 can be further improved.

  A plurality of connectors are provided on a side surface of the housing 910, that is, both end surfaces of the control device 900 in the short direction. As the plurality of connectors, a voltage detection connector 912, a temperature detection connector 913, and an external connection connector 911 are provided. The voltage detection connector 912 is coupled to the connector of the connection wiring 800 that is electrically connected to the 32 battery cells 140. A connector for signal lines 941 of a plurality of temperature sensors (not shown) disposed inside the power storage module 100 is coupled to the temperature detection connector 913.

  A connector 911 for external connection is used for CAN communication with a power line for supplying driving power to the battery controller 300, a signal line for inputting an on / off signal of an ignition key switch, and the vehicle controller 30 and the motor controller 23. A connector (not shown) such as a communication line is coupled.

[Method for Manufacturing Power Storage Device]
A method for manufacturing power storage device 1000 including power storage module 100 and control device 900 described above, in particular, an assembly method will be described with reference to the flowchart of FIG.
In FIG. 13, steps S <b> 1 to S <b> 11 are steps for manufacturing the power storage module 100.
The power storage device 1000 includes a high potential side power storage module 100a and a low potential side power storage module 100b. The high potential side power storage module 100a and the low potential side power storage module 100b have the same structure, Depending on the connection method used when connecting the power storage module to the control device 900, it is determined as one. That is, the method for assembling the power storage module 100 is the same, and the method for creating the power storage module 100 described below is common to the high potential side and the low potential side.

When the assembly of the high potential side power storage module 100a and the low potential side power storage module 100b is started, the case body 110 and the case side plates 130 and 131 are prepared in step S1.
The case body 110 includes an inlet flow path forming part 111, an outlet side guide part 113, a cooling medium inlet 114 and a cooling medium inlet duct 116, an outlet flow path forming part 118, an inlet side guide part 112, a cooling medium outlet 115 and a cooling medium. The medium outlet duct 117 is integrally formed. Such a case main body 110 can be produced by an aluminum die casting method as an example.

The case side plates 130 and 131 can be manufactured by the same method. Here, the production of the case side plate 130 will be described.
First, the voltage detection conductor 805 is manufactured. For this purpose, the detection wire 806 connected to the connection terminal 810 and the current interrupting portion 811 is insert-molded using, for example, PBT as a molding material to form a resin portion 807 that is a primary molding portion. The resin portion 807 includes a plurality of joint portions 820 having a fixing portion 821 and a meltable portion 822.

Next, the voltage detection conductor 805 is mounted on a secondary molding die, and insert molding is performed using, for example, PBT as a molding material to form the case side plate 130. In this case, as described above, in the voltage detection conductor 805 attached to the secondary molding die, the upper surface 821a of the upper and lower fixing portions 821 of the resin portion 807 is clamped by the secondary molding die. For this reason, the detection line 806 fixed to the resin portion 807 is reliably fixed at a predetermined position in the height direction in the mold.
Further, the edge portion 822a of the meltable portion 822 is melted by heat and pressure at the time of injection of the secondary molding material, and fused with the secondary molding material. For this reason, the resin portion 807 and the secondary molded portion 130 ′ are firmly joined at the edge portion 822a and the vicinity thereof.

After producing the case side plates 130 and 131 in which the case body 110 and the voltage detection conductor 805 are integrated, the assembly shown in step S2 is performed.
In step S <b> 2, first, an adhesive for bonding the positive electrode terminal 140 a or the negative electrode terminal 140 b of the battery cell 140 is applied to the case side plates 130 and 131.
Then, one of the case side plates 130 and 131, here exemplified as the case side plate 131, is fastened to the case main body 110 by a fastening member.

Next, in step S <b> 3, the battery cell 140 is stored in the case main body 110.
In step S2, the case assembly in which the case main body 110 and the case side plate 131 are fastened is set on a mounting base (not shown) with the case side plate 131 facing down.
Then, the battery cell 140 is inserted into the case main body 110. Each battery cell 140 is inserted through the case main body 110 in the height direction and sequentially inserted using a ring-shaped rib (not shown) formed on the case side plate 131 as a guide.

Next, in step S4, the case side plate 130 is fixed to the case main body 110 with a fastening member.
Thereby, the positive terminal 140a and the negative terminal 140b of the battery cell 140 are adhered and fixed to the adhesive applied to the case side plates 130 and 131. Further, in each battery cell 140 accommodated in the case body 110, a part of the positive / negative electrode terminals 140 a and 140 b is exposed from the side plate through hole 132 of the case side plate 130.

Next, in step S <b> 5, the bus bar 150 is welded to the positive and negative terminals 140 a and 140 b of each battery cell 140 exposed from the side plate through hole 132 of the case side plate 130.
First, each bus bar 150 is attached to the case side plate 130. The bus bar 150 is attached by fitting the positioning hole 155 of the bus bar 150 to the fixed guide 130a of the case side plate 130 (see FIG. 11). Thereby, the electrode joining part 152 of each bus-bar 150 is positioned in the required location of the positive / negative terminal 140a, 140b of the battery cell 140. FIG.

In this state, the bus bar 150 is joined to the positive and negative terminals 140a and 140b of each battery cell 140.
For this purpose, the electrode joint 152 of the bus bar 150 aligned with the positive and negative terminals 140a, 140 of the battery cell 140 is joined by, for example, TIG (Titan Inert Gas) welding, gas shield arc welding, or the like.

  Next, in step S6, the bus bar 150 and the tip end portion 800a of the voltage detection conductor 805 are connected. Specifically, the tip end portion 800a of the voltage detection conductor 805 is brought into contact with the rising portion 159 of the bus bar 150, and in this state, for example, is joined by TIG welding.

  Next, in step S7, the cover plate 160 is assembled to the case side plate 130 via a seal member (not shown) and fixed by a fastening member 161 (see FIG. 4) such as a bolt, a screw, or a rivet. The seal member is an elastic seal member (for example, a rubber O-ring), and is fitted into a groove formed in the case side plate 130. A liquid gasket may be used as the seal member.

  Next, in step S8, the assembly in which the battery cell 140 is stored and the cover plate 160 and the case side plate 130 are fastened to the case main body 110 is turned upside down, and the case side plate 131 faces upward.

Next, in step S <b> 9, the bus bar 150 is attached to the case side plate 131.
This process is performed in the same manner as step S5, and the description thereof is omitted here.

Next, in step S10, the bus bar 150 and the tip end portion 800a of the voltage detection conductor 805 are connected.
This process is performed in the same manner as step S6, and the description thereof is omitted here.

Next, in step S11, the other cover plate 160 is assembled to the case side plate 131 via a seal member (not shown) and fixed by a fastening member 161 such as a bolt, a screw, or a rivet.
This process is performed in the same manner as step S7, and the description thereof is omitted here.

When step S11 is completed, one power storage module 100 is manufactured.
Steps S1 to S11 are repeated to produce power storage modules 100a and 100b.
Next, in step S12, the module base 101 (FIG. 2, FIG. 2) in the state where the power storage modules 100a and 100b assembled by the method shown in step S1 to step S11 are juxtaposed so that their longitudinal directions are parallel to each other. 3). The module base 101 is fixed to the bottom of the case body 110 by fastening means such as bolts, screws, rivets and the like.

And the housing | casing of the control apparatus 900 is fixed to fastening parts, such as a volt | bolt, a screw | thread, and a rivet, to the longitudinal direction center part of the two electrical storage modules 100a and 100b.
The connector of the connection wiring 800 of each power storage module 100 is connected to the connection terminal 810 of each power storage module 100 and the voltage detection connector 912 of the control device 900. The control device 900 is provided with an SD switch 700 having one end connected to the high potential side of the high potential side power storage module 100a and the other end connected to the negative electrode side of the low potential side power storage module 100b.

A signal line connector extending from a plurality of temperature sensors (not shown) provided in each power storage module 100a, 100b is connected to a temperature detection connector 913 of the control device 900. Further, a connector of a communication line for communicating with the host controller, for example, the vehicle controller 30 and the motor controller 23 is connected to the connector of the controller 900.
The power storage device 1000 is completed through the assembly operations of steps S1 to S12 described above.

  Note that the method of assembling the power storage module device is not limited to the above-described method. For example, the bus bar 150 may be assembled to the case side plates 130 and 131 in advance, or may be attached to the case side plates 130 and 131 by insert molding. Various changes can be made, such as integration.

Next, in step S8, the connector of the connection line 800 is connected to the connection terminal 810 of the power storage module device and the connector 912 of the control device 900, respectively. A connector of a signal line 941 extending from a plurality of temperature sensors (not shown) provided in each of the power storage modules 100a and 100b of the power storage module device is connected to the connector 913 of the control device 900.
The power storage device 1000 is completed through the assembly operations of steps S1 to S8 described above.

[Effect of the embodiment]
In the power storage modules 100a and 100b according to the embodiment described above, in the voltage detection conductor 805, the resin portion 807 that is a primary molded portion has a fixed portion 821 and a meltable portion 822 having an edge portion 822a. It has.
For this reason, at the time of injection of the secondary molding material, the resin portion 807 is melted at the edge portion 822a by the heat and injection pressure of the secondary molding material and fused with the secondary molding material. As a result, when the secondary molding material is cooled, the resin portion 807 that is the primary molding portion and the secondary molding portion 130 ′ are firmly joined at the edge portion 822 a and in the vicinity thereof. As a result, it is possible to prevent the primary molded part and the secondary molded part from being separated even under an environment where temperature and impact are severe.

  In the above-described embodiment, in the voltage detection conductor 805, the resin portion 807 that is a primary molding portion includes the fixing portion 821 having the upper surface 821a. The upper surface 821a of the fixing portion 821 is pressed by the secondary molding die and fixed in the height direction in the die. For this reason, the detection line 806 integrated with the resin portion 807 is fixed at a predetermined position in the thickness direction of the secondary molded portion 130 ′. Accordingly, it is possible to prevent the detection line 806 and the resin portion 807 from being exposed to the outer surface of the case side plates 130 and 131 and being damaged or deteriorating the appearance.

In the above embodiment, the edge portion 822a of the meltable portion 822 formed between the fixing portion 821 and the main body portion 808 is formed in a circular shape and closed so as not to be exposed to the outside of the secondary molding portion 130 ′. It is formed in a planar shape.
Therefore, even if mist-like gas flows into the boundary portion between the fixed portion 821 and the secondary molding portion 130 ′, it is blocked by the edge portion 822 a where the primary molding material and the secondary molding material are fused, and inside the case side plate 130. Inflow can be prevented.

In the above-described embodiment, the resin portion 807 that is a primary molding portion and the secondary molding portion 130 ′ are formed of the same molding material, for example, PBT.
For this reason, the primary molded part and the secondary molded part are not peeled off due to the difference in linear expansion coefficient, and high reliability can be ensured even when used in an environment where the thermal shock is severe.

According to the power storage modules 100a and 100b according to the embodiment described above, the following effects can be obtained in addition to the effects described above.
(1) The power storage modules 100a and 100b include a plurality of battery cells 140, a case main body 110 that houses the plurality of battery cells 140, a plurality of bus bars 150 that electrically connect the plurality of battery cells 140, and a plurality of The voltage detection conductor 805 for detecting each voltage of the battery cell 140 is provided. The case main body 110 includes at least a pair of resin case side plates 130 and 131 that sandwich and support a plurality of battery cells 140 from both sides. As shown in FIGS. 6 and 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 150 are attached to the case side plates 130 and 131 from the outside of the case body 110 in order to connect the plurality of battery cells 140. Thereby, the bus bar 150 and each battery cell 140 can be easily connected.

(3) The tip 800a of the voltage detection conductor 805 is connected to the plurality of bus bars 150, and the other end of the voltage detection conductor 805 is a current interrupt device (current interrupter) 811 that interrupts the current from the battery cell 140. Is provided. The current interrupting unit 811 protects the product by cutting off the current from the 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) In the case side plates 130 and 131, side plate through holes 132 are formed at positions corresponding to the plurality of battery cells 140. In each battery cell 140, the positive and negative terminals 140a and 140b are bonded to the case side plates 130 and 131. Bonded by the agent. 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 battery cell 140 can be maintained while absorbing an external force applied to the power storage module 100, such as vibration, 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 150. A collision-preventing fixed guide 130a and a protrusion 136 for preventing the contact between the two. 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 body 110, the cover plate 160 first contacts the fixed guide 130 a or the protrusion 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 150 contact, for example, and a short circuit generate | occur | produces. Further, since the protrusion 136 surrounds the entire periphery of the bus bar 150 except for the vicinity of the front end portion 800a, it can withstand various external forces.

(7) The power storage device 1000 includes the power storage module 100 and a control device 900 that detects the voltage of the plurality of battery cells 140 connected to the voltage detection conductor 805 and controls the amount of power stored in the plurality of battery cells 140. 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.

[Modification of Embodiment]

  In the embodiment described above, the power storage module device including the two power storage modules 100a and 100b to which the 16 battery cells 140 are connected is illustrated. However, the present invention is not limited to the configuration and connection method (series and parallel) of the power storage modules 100a and 100b described above, but relates to a configuration in which the number of battery cells 140, the number, arrangement, and direction of battery cell rows are changed. Also applies.

  In the embodiment described above, the battery container is composed of the case main body 110, the pair of case side plates 130 and 131 disposed on both side surfaces of the case main body 110, and the cover plate 160 disposed on the outside of each case side plate 130 and 131. It was illustrated as a structure composed of However, the battery container is not limited to those formed from such components. For example, one of the case side plates 130 and 131 may be formed integrally with the case main body 110. Alternatively, various modifications can be made such as a vertically divided structure of a lower case having a battery storage portion and an upper case covering the battery storage portion.

In the embodiment described above, in the voltage detection conductor 805, the joint portion 820 of the resin portion 807 that is a primary molded portion is exemplified as a structure in which the fixing portion 821 and the meltable portion 822 are each formed in a columnar shape. However, the shape is not limited to a cylindrical shape, and may be a cross-sectional shape, an elliptical shape, or a polygonal columnar shape. Moreover, it is good also as not a pillar shape but a dome shape, a truncated cone, and a polygonal truncated cone.

  Although the cross-sectional shapes of the fixing portion 821 and the meltable portion 822 in the joint portion 820 are exemplified as the same shape, the cross-sectional shapes of the fixing portion 821 and the meltable portion 822 may be different shapes. Further, the axis of the fixing portion 821 and the meltable portion 822 may not be coaxial. The angle of the edge part 822a of the meltable part 822 is not limited to a right angle, and may be a little larger than the right angle or an acute angle. Further, the edge portion 822a may be formed in a plurality of locations in a spiral shape, a concentric circle shape, or a lattice shape in the height direction or in a direction parallel to the detection line 806.

  The joint portion 820 is preferably formed so as to be opposed to the upper and lower sides of the detection line 806. However, the shape and size of the cross-sectional area may be different. Each joint 820 is not necessarily provided with both the fixed part 821 and the meltable part 822, and may be a joint part 820 composed of only the fixed part 821 or only the meltable part 822. However, it is preferable to form at least one or two pairs of fixing portions 821 formed so as to be opposed to the upper and lower sides of the detection line 806.

In the embodiment described above, a cylindrical lithium ion secondary battery cell is exemplified as the battery cell 140, but the present 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 battery cell but to capacitors, such as cylindrical lithium ion.

  The power storage device 1000 according to the embodiment described above is used for vehicles such as other electric vehicles, for example, railway vehicles such as hybrid trains, passenger cars such as buses, cargo vehicles such as trucks, and industrial vehicles such as battery-type forklift trucks. It can also be used for a power supply device.

  The power storage device 1000 according to the embodiment is also 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 It doesn't matter.

  In addition, the power storage module of the present invention can be variously modified and configured within the scope of the invention. In short, a case main body in which a plurality of power storage cells are stored, and a case main body. Connected to the electrode terminal of the storage cell, and a case side plate integrally formed with a connection conductor for detecting the voltage of the storage cell, the case side plate is a primary in which at least a part of the connection conductor is formed integrally A molding part and a secondary molding part formed so as to cover the primary molding part, and the primary molding part is formed in a protruding shape from the main body part covering the outer surface of the connecting conductor, and the secondary molding part. What is necessary is just to have the fixing | fixed part which has the exposed surface exposed to the outer surface of this, and the meltable part provided between the main-body part and the exposed surface of the fixing | fixed part.

Further, in the method for manufacturing a power storage module according to the present invention, the connection body for detecting the voltage of the power storage cell is integrally formed with the case body in which the plurality of power storage cells are housed, connected to the electrode terminal of the power storage cell. A method of manufacturing a power storage module to which a case side plate is attached,
The step of forming the case side plate is a step of forming a primary molded body having a main body portion that covers the connection conductor, a fixing portion protruding from the main body portion, and a meltable portion provided on the main body portion side of the fixing portion, and The process may include a step of forming a secondary molded body that covers the outer surface of the primary molded body in a state where the fixing portion of the primary molded body is fixed.

100a, 100b power storage module,
110 Case body,
140 battery cell 140a positive electrode terminal 140b negative electrode terminal 150, 150a, 150b bus bar 130, 131 case side plate,
130 'Secondary forming part 160 Cover plate 805 Voltage detection conductor 806 Detection line 807 Resin part 808 Main body part 820 Joining part 821 Fixing part 821a Upper surface 822 Meltable part 822a Edge part 900 Control apparatus 1000 Power storage device

Claims (10)

A case body containing a plurality of storage cells;
A case side plate connected to an electrode terminal of the electricity storage cell housed in the case body and integrally formed with a connection conductor for detecting the voltage of the electricity storage cell;
The case side plate has a primary molded part in which at least a part of the connection conductor is integrally formed, and a secondary molded part formed to cover the primary molded part,
The primary molding portion includes a main body portion that covers an outer surface of the connection conductor, a fixing portion that is formed in a protruding shape from the main body portion and is exposed to the outer surface of the secondary molding portion, and the main body portion. A power storage module comprising a meltable portion provided between an exposed surface of the fixed portion.   The power storage module according to claim 1, wherein the primary molding part and the secondary molding part are formed of the same resin material.   3. The power storage module according to claim 1, wherein a main body portion of the primary molding portion is formed to cover both upper and lower surfaces of the connection conductor, and the fixing portion and the meltable portion are formed on upper and lower surfaces of the connection conductor. A power storage module formed.   4. The power storage module according to claim 3, wherein the fixing portion and the meltable portion formed so as to cover the upper and lower surfaces of the connection conductor are formed on the same axis. 5.   5. The power storage module according to claim 1, wherein the meltable portion includes an edge portion, and the edge portion is formed in a closed planar shape that is not exposed to the outside of the secondary molding portion. A power storage module.   6. The power storage module according to claim 1, wherein the fixing portion is formed in a columnar shape, and the meltable portion has a planar shape larger than the fixing portion and a height lower than the fixing portion. A power storage module formed in a columnar shape.   The power storage module according to any one of claims 1 to 6, wherein the connection conductor has a lead-out portion that protrudes to the outside of the secondary molding portion.   8. The power storage module according to claim 1, wherein the primary molding unit includes a plurality of the fixing unit and the meltable unit. 9. Manufacture of a power storage module in which a case side plate that is connected to an electrode terminal of the power storage cell and integrally formed with a connection conductor for detecting the voltage of the power storage cell is attached to a case body that houses a plurality of power storage cells A method,
The step of forming the case side plate includes:
Forming a primary molded body having a main body portion covering the connection conductor, a fixing portion protruding from the main body portion, and a meltable portion provided on the main body side of the fixing portion;
Forming a secondary molded body that covers an outer surface of the primary molded body in a state where the fixing portion of the primary molded body is fixed. 10. The method of manufacturing an electricity storage module according to claim 9, wherein the fixing portion is formed in a columnar shape, and the meltable portion is formed in a columnar shape having a planar shape larger than the fixing portion and a height lower than the fixing portion. A method for manufacturing a power storage module.

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