Battery module

Abstract

In a battery module in which an intermediate bus bar is disposed in a storage space formed on a side surface of a stacked unit, the sensor unit includes: a sensor housing that is stored in the storage space so as to be in contact with the intermediate bus bar; and a first clip that is electrically connected to a sensor circuit within the sensor housing and, when the sensor housing is stored in the storage space, is disposed at a position opposite to the intermediate bus bar within the sensor housing and can be engaged with the intermediate bus bar. By engaging the first clip with the intermediate bus bar, the sensor housing is fixed to the intermediate bus bar, and the sensor circuit is electrically connected to the intermediate bus bar by means of the first clip.

Description

Technical Field

[0001] The present invention relates to a battery module. Background Art

[0002] JP2021-18133A discloses a structure in which a sensor unit for monitoring the state of battery cells is mounted on a stacked unit formed by stacking a plurality of battery cells. Summary of the Invention

[0003] However, in JP2021-18133A, when mounting the sensor unit and the stacked unit, a wiring connection operation for connecting the wiring of the sensor unit to the electrode wiring of the stacked unit is required, increasing the number of components and the assembly process. In addition, the wiring removal operation during reuse / recycling becomes complicated. Also, in the wiring connection operation and the wiring removal operation, a countermeasure for preventing short circuits in the stacked unit is required. Moreover, when the sensor unit is optimized for in-vehicle use and the stacked unit is separated and reused for secondary use of the battery cells, a new specification sensor unit needs to be installed, and the above problems arise again at this time.

[0004] An object of the present invention is to provide a battery module that can avoid complicated wiring connection operations and wiring removal operations, further avoid short-circuit prevention countermeasures, and can mount a sensor unit on a stacked unit.

[0005] The battery module of the present invention includes: a stacked unit formed by stacking a plurality of battery cells; a bus bar connected to the battery cells; and a sensor unit electrically connected to the bus bar and including a sensor circuit for measuring the state of the battery cells. In this battery module, the bus bar is disposed in a storage space formed on one side surface of the stacked unit, and the sensor unit includes: a sensor housing that houses the sensor circuit and is formed to resemble the shape of the bus bar and is housed in the storage space in contact with the bus bar; and a fitting portion that is electrically connected to the sensor circuit and is disposed at a position opposite to the bus bar in the sensor housing when the sensor housing is housed in the storage space and can be fitted to the bus bar. And by fitting the fitting portion to the bus bar, the sensor housing is fixed to the bus bar, and the sensor circuit is electrically connected to the bus bar via the fitting portion. Brief Description of the Drawings

[0006] Figure 1 It is a perspective view of a stacked unit constituting the battery module of the present embodiment.

[0007] Figure 2 It is a diagram showing a region in the storage space formed in the stacked unit where a sensor unit or the like can be mounted.

[0008] Figure 3 It is an exploded perspective view of the battery module of the present embodiment.

[0009] Figure 4A This is a perspective view of the sensor unit that constitutes the battery module of the present embodiment.

[0010] Figure 4B This is a cross-sectional view of the sensor unit that constitutes the battery module of the present embodiment.

[0011] Figure 5 This is a cross-sectional view showing the connection state of the sensor unit.

[0012] Figure 6 This is Figure 5 a partial detailed view of

[0013] Figure 7 This is a circuit diagram of the sensor unit, battery cell, positive bus bar, negative bus bar, and intermediate bus bar.

[0014] Figure 8 This is a perspective view of the first modification of the battery module of the present embodiment.

[0015] Figure 9A This is a plan view of the sensor power supply unit of the first modification.

[0016] Figure 9B This is a cross-sectional view before the sensor power supply unit of the first modification is sandwiched between the positive bus bar and the negative bus bar.

[0017] Figure 9C This is a cross-sectional view after the sensor power supply unit of the first modification is sandwiched between the positive bus bar and the negative bus bar.

[0018] Figure 9D This is a cross-sectional view when the sensor power supply unit of the first modification is fixed with a clip.

[0019] Figure 10 This is a circuit diagram of the sensor unit, battery cell, positive bus bar, negative bus bar, intermediate bus bar, and sensor power supply unit of the first modification.

[0020] Figure 11 This is a diagram showing an example of a jumper extending from the sensor unit.

[0021] Figure 12 This is a diagram showing an example of a clip attached to the sensor housing.

[0022] Figure 13 This is the second modification of the battery module of the present embodiment, and it is a circuit diagram of the sensor unit, battery cell, positive bus bar, negative bus bar, and intermediate bus bar. Detailed implementation mode

[0023] Hereinafter, while referring to the attached Figure 1The embodiments of the present invention will be described below.

[0024] [Structure of Stacking Unit 1]

[0025] Figure 1 FIG. 7 is a perspective view of a stacking unit 1 that constitutes a battery module according to the present embodiment. In the present embodiment, the stacking unit 1 is formed by stacking a plurality (e.g., four) battery cells 11 (S1, S2, S3, S4). The battery cell 11 has, for example, a power storage unit 111 formed of a lithium-ion battery or the like, and fastening units 112 disposed at both ends of two long sides (or short sides) of the power storage unit 111. Then, the stacking unit 1 is formed by stacking the battery cells 11 and, for example, riveting and fastening the fastening units 112.

[0026] Thin plate portions 12 are disposed at positions of the battery cells 11 at both ends in the thickness direction of the stacking unit 1 and sandwiched by the two fastening units 112. And the region surrounded by the fastening unit 112 and the thin plate portion 12 becomes a storage space 14 that can store a positive electrode bus bar 2, a negative electrode bus bar 3, an intermediate bus bar 4, a sensor unit 5 ( Figure 3 ), etc.

[0027] The battery cell 11 has: a positive electrode unit lead plate 113 that extends from the positive electrode of the power storage unit 111 and is disposed in the storage space 14; and a negative electrode unit lead plate 114 that extends from the negative electrode of the power storage unit 111 and is disposed in the storage space 14.

[0028] The positive electrode bus bar 2 has a positive electrode external terminal P for connection to the outside, and is connected to the positive electrode unit lead plate 113 (P1) of the lowermost battery cell 11 (S1) and the positive electrode unit lead plate 113 (P2) of the second battery cell 11 (S2) from the bottom in the order of being electrically closer to the positive electrode external terminal P, as shown in Figure 1 ( Figure 7 ). In addition, the positive electrode bus bar 2 is supported by the positive electrode unit lead plate 113 (P1) and the positive electrode unit lead plate 113 (P2).

[0029] The negative electrode bus bar 3 has a negative electrode external terminal N for connection to the outside, and is connected to the negative electrode unit lead plate 114 (N3) of the second battery cell 11 (S3) from the top and the negative electrode unit lead plate 114 (N4) of the uppermost battery cell 11 (S4) (not shown in Figure 1 , refer to Figure 1 Figure 3 Figure 7

[0030] ) in the order of being electrically closer to the negative electrode external terminal N. In addition, the negative electrode bus bar 3 is supported by the negative electrode unit lead plate 114 (N3) and the negative electrode unit lead plate 114 (N4).

[0030] The intermediate bus bar 4 has an intermediate external terminal M connected to the outside. In the order of being electrically close to the intermediate external terminal M, it is connected to the negative unit lead plate 114(N1) of the battery cell 11(S1), the negative unit lead plate 114(N2) of the battery cell 11(S2), the positive unit lead plate 113(P3) of the battery cell 11(S3), and the positive unit lead plate 113(P4) of the battery cell 11(S4). Figure 7 ) In addition, the intermediate bus bar 4 is supported by the negative unit lead plate 114(N1), the negative unit lead plate 114(N2), the positive unit lead plate 113(P3), and the positive unit lead plate 113(P4).

[0031] According to the above connection form, the positive electrodes of the battery cells 11(S1) and 11(S2) are connected in parallel by the positive bus bar 2, and the positive electrodes of the battery cells 11(S1) and 11(S2) become the positive electrode of the stacked unit 1. Figure 7 ) In addition, the negative electrodes of the battery cells 11(S3) and 11(S4) are connected in parallel by the negative bus bar 3, and the negative electrodes of the battery cells 11(S3) and 11(S4) become the negative electrode of the stacked unit 1. Figure 7 ) Moreover, the negative electrodes of the battery cells 11(S1), 11(S2), the positive electrode of the battery cell 11(S3), and the positive electrode of the battery cell 11(S4) are connected in parallel to the intermediate bus bar 4. Figure 7 )

[0032] In addition, the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4 are bent into a stepped shape in the storage space 14 in a manner of being connected to each unit lead plate and not contacting other bus bars.

[0033] In addition, in the storage space 14, a stopper 141 is arranged close to the bus bar. When the bus bar vibrates relative to the stacked unit 1 due to external vibration, the bus bar preferentially abuts against the stopper 141 to prevent the bus bar from contacting other bus bars.

[0034] Figure 2 It is a diagram showing the area where the installable sensor unit 5 and the like are formed in the storage space 14 of the stacked unit 1. As Figure 2 shown, in the storage space 14, a plurality of divided spaces (the first divided space 142, the second divided space 143, the third divided space 144) (the parts surrounded by thick lines) are formed by the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4. In this embodiment, the sensor unit 5 described later is arranged in the first divided space 142, but it can also be arranged in the second divided space 143 or the third divided space 144.

[0035] For example, in the case where the storage space 14 is divided into relatively fine sections by busbars (positive busbar 2, negative busbar 3, intermediate busbar 4), the sensor section 5 (sensor circuit 52 described later) is divided into multiple sections, and a number of divided sensor housings (sensor housings 51 described later) equal to the number of sensor sections 5 are prepared. The divided sensor circuits (sensor circuits 52 described later) are housed in the respective divided sensor housings (sensor housings 51) and are respectively arranged in the storage space 14. Thus, even if there are multiple, but relatively small-sized divided sensor housings (sensor housings 51) are arranged in the storage space 14. Therefore, they can be arranged in a manner that does not interfere with the busbars, and the degree of freedom in the design of the battery module can be improved.

[0036] [Structure of the battery module]

[0037] Figure 3 is an exploded perspective view of the battery module of the present embodiment. The battery module of the present embodiment includes the above-described stacking unit 1, sensor section 5, sub-circuit section 6, and terminal cover 7 (cover). In the battery module of the present embodiment, the sensor section 5 and the sub-circuit section 6 are arranged in the storage space 14, and the terminal cover 7 is inserted into the side surface of the stacking unit 1 so as to cover the storage space 14 (sensor section 5, sub-circuit section 6).

[0038] The sensor section 5 is arranged in the storage space 14, for example, in the first divided space 142 formed between the thin plate section 12 and the intermediate busbar 4 ( Figure 2 ), and has a sensor housing 51 with an outer shape similar to the shape of the first divided space 142, that is, the stepped shape of the intermediate busbar 4. In Figure 3 , the number of steps of the surface of the sensor housing 51 facing the intermediate busbar 4 can be arbitrarily set according to the number of connection points between the unit lead plates of the sensor circuit 52. The sensor housing 51 only needs to be in a shape that can be inserted into the stepped first divided space separated by at least the intermediate busbar 4. For example, a sensor circuit 52 for detecting the state (output voltage, internal resistance) of the battery cell 11 is arranged in the sensor housing 51 ( Figure 4B ).

[0039] Conductive first clips 53 are arranged at positions of the sensor housing 51 facing the respective steps (where unit lead plates are arranged) of the intermediate busbar 4. The first clips 53 are leaf spring-shaped contacts, made of, for example, phosphor bronze, and have appropriate elastic force and resistance.

[0040] The first clips 53 are connected to the sensor circuit 52 ( Figure 4B) Electrically connect. Additionally, sandwich the intermediate bus bar 4 (and the unit lead plate) between the first clip 53 and the sensor housing 51, and apply the pressing force of the first clip 53 to the intermediate bus bar 4, so that the sensor housing 51 is fixed relative to the intermediate bus bar 4 (unit lead plate), and the sensor circuit 52 and the intermediate bus bar 4 (unit lead plate) are electrically connected to each other by means of the first clip 53.

[0041] In addition, it can also be that the outer shape of the sensor housing 51 is designed with a size slightly larger than the size of the first divided space 142 formed between the thin plate portion 12 and the intermediate bus bar 4, and the sensor housing 51 is arranged in the first divided space 142 in a form of being press-fitted into the first divided space 142. Thus, the sensor housing 51 is fixed to the first divided space 142 by the pressing force of the first clip 53 and the pressing force of the sensor housing 51 on the intermediate bus bar 4. Therefore, the burden on the first clip 53 can be correspondingly reduced (the same applies to the sub-circuit portion 6 described later).

[0042] A first connection terminal 521 is arranged on the surface of the sensor housing 51 opposite to the terminal cover 7. The first connection terminal 521 is used as, for example, a power input terminal for supplying power to the sensor circuit 52, a terminal for two-way communication with the sub-circuit portion 6, etc. The first connection terminal 521 is arranged to protrude from the sensor housing 51 toward the terminal cover 7 side, and abuts against the second wiring 73 arranged on the inner wall of the terminal cover 7 when the terminal cover 7 is inserted into the stacked unit 1. In addition, the first connection terminal 521 has, for example, the same structure as that of the first clip 53, and preferably has the following structure: due to being deformed by the pressing force received from the terminal cover 7, it can apply the restoring force generated by the deformation to the terminal cover 7 (the first wiring 72). Thus, the electrical connection between the first connection terminal 521 and the first wiring 72 can be ensured.

[0043] The sub-circuit portion 6 is arranged, for example, in the second divided space 143 formed between the positive bus bar 2 and the negative bus bar 3 in the accommodation space 14 Figure 2 ), and has a circuit housing 61 (corresponding to the holding member 61a described later) with an outer shape similar to the shape of the second divided space 143.

[0044] The sub-circuit 62 arranged in the circuit housing 61 Figure 7 ) is a circuit for assisting the sensor circuit 52, such as a sensor communication circuit in the BLE (Bluetooth (registered trademark) Low Energy) method for two-way communication with the outside regarding information obtained from the sensor power supply circuit 62a Figure 9A 、 Figure 9B 、 Figure 9C 、 Figure 9D ) for supplying power to the sensor unit 5, the sensor circuit 52, etc.

[0045] The second clip 63 is disposed at a position of the circuit case 61 facing the positive bus bar 2, and the third clip 64 is disposed at a position of the circuit case 61 facing the negative bus bar 3. The second clip 63 and the third clip 64 have the same structure as the first clip 53.

[0046] The second clamp 63 and the auxiliary circuit 62 ( Figure 7 , Figure 9A , Figure 9B , Figure 9C , Figure 9D The positive bus bar 2 is clamped between the second clamp 63 and the circuit housing 61, and the pressing force of the second clamp 63 is applied to the circuit housing 61 and the positive bus bar 2, so that the circuit housing 61 is fixed to the positive bus bar 2, and the auxiliary circuit 62 is electrically connected to the positive bus bar 2 by means of the second clamp 63.

[0047] The third clamp 64 is connected to the auxiliary circuit 62 ( Figure 7 , Figure 9A , Figure 9B , Figure 9C . Figure 9D The negative bus bar 3 is clamped between the third clamp 64 and the circuit housing 61, and the pressing force of the third clamp 64 is applied to the circuit housing 61 and the negative bus bar 3, so that the circuit housing 61 is fixed to the negative bus bar 3, and the auxiliary circuit 62 is electrically connected to the negative bus bar 3 by means of the third clamp 64.

[0048] The second connection terminal 622 is disposed on the surface of the circuit case 61 facing the terminal cover 7. The second connection terminal 622 is used as, for example, a power output terminal for supplying power to the sensor circuit 52, a terminal for bidirectional communication with the sensor circuit 52, or the like.

[0049] The second connecting terminal 622 has the same structure as the first connecting terminal 521 and is configured to protrude from the circuit housing 61 toward the terminal cover 7 so as to abut against the first wiring 72 arranged on the inner wall of the terminal cover 7 when the terminal cover 7 is embedded in the stacking unit 1 .

[0050] The terminal cover 7 is a member having an inner wall in contact with the outer walls of the two thin plate portions 12 of the stacking unit 1. The terminal cover 7 is formed of an electrically insulating material having a magnetic effect, similarly to the sensor housing 51, and its surface is covered with an insulating layer (not shown) such as resin, as will be discussed later.

[0051] By inserting the terminal cover 7 from the opening of the storage space 14 , the terminal cover 7 is attached to the stacking unit 1 so as to cover the storage space 14 .

[0052] The terminal cover 7 is provided with through holes 71 into which the positive external terminal P, the negative external terminal N, and the middle external terminal M are respectively inserted. When the terminal cover 7 is attached to the stacking unit 1 , the external terminals are arranged in the through holes 71 .

[0053] In addition, the first wiring 72 and the second wiring 73 are arranged on the insulating layer (not shown) of the inner wall of the terminal cover 7. On the other hand, the third wiring 131 is arranged on the outer wall of the thin plate portion 12, and the third wiring 131 extends in the direction connecting the pair of fastening portions 112, and at one of the two ends of the third wiring 131, it extends in the direction toward the first connection terminal 521 of the sensor housing 51 when viewed in a plan view, and at the other of the two ends of the third wiring 131, it extends in the direction toward the second connection terminal 622 of the auxiliary circuit portion 6. The first wiring 72, the second wiring 73, and the third wiring 131 are all formed of, for example, a Cu (copper) tape.

[0054] When the terminal cover 7 is mounted on the stacking unit 1 , one end of the first wiring 72 is arranged at a position facing the second connection terminal 622 , and the other end is arranged at a position facing the third wiring 131 .

[0055] When the terminal cover 7 is mounted on the stacking unit 1 , one end of the second wiring 73 is arranged at a position facing the first connection terminal 521 , and the other end is arranged at a position facing the third wiring 131 .

[0056] Therefore, when the terminal cover 7 is mounted on the stacking unit 1, one end of the first wiring 72 contacts the second connection terminal 622, and the other end contacts the third wiring 131. In addition, one end of the second wiring 73 contacts the first connection terminal 521, and the other end contacts the third wiring 131. Thus, the first connection terminal 521 and the second connection terminal 622 are electrically connected to each other via the first wiring 72, the second wiring 73, and the third wiring 131. In addition, the third wiring 131 may be omitted, as shown in FIG. Figure 3 As shown in the terminal cover 7 (in the portion surrounded by the rectangular dotted line), a fourth wiring 74 is arranged on the inner wall of the terminal cover 7 so as to connect the first wiring 72 and the second wiring 73 to each other.

[0057] In addition, for example, the sensor circuit 52 in the sensor unit 5 and the sub-circuit 62 in the sub-circuit unit 6 ( Figure 7 , Figure 9A , Figure 9B , Figure 9C , Figure 9D ) can perform two-way wireless communication. When a small battery is built into the sensor circuit 52 and no external power supply is required, the first connecting terminal 521, the second connecting terminal 622, the first wiring 72, the second wiring 73, the third wiring 131, and the fourth wiring 74 can be omitted.

[0058] [Sensor unit]

[0059] Figure 4A This is a perspective view of the sensor unit 5 that constitutes the battery module of this embodiment. Figure 4B This is a cross-sectional view of the sensor unit 5 that constitutes the battery module of this embodiment. Figure 4A It shows the state where the sensor unit 5 is mounted on the intermediate bus bar 4.

[0060] As Figure 4A shown, the intermediate bus bar 4 has a four-step shape, and unit lead plates extending from the battery cells 11 are arranged at each step. The unit lead plates arranged on the intermediate bus bar 4 are, for example, Figure 4A in order from the top, the positive unit lead plate 113 (P4) of the battery cell 11 (S4), the positive unit lead plate 113 (P3) of the battery cell 11 (S3), the negative unit lead plate 114 (N2) of the battery cell 11 (S2), and the negative unit lead plate 114 (N1) of the battery cell 11 (S1).

[0061] The sensor housing 51 (similarly for the circuit housing 61 described above) is formed of an electrically insulating material having a magnetic effect and can electrostatically shield the inside of the housing.

[0062] Among them, the sensor housing 51 is manufactured by sheet metal or stamping a metal material with a relatively high magnetic permeability such as an iron plate or a steel plate, or by die-casting or hot-pressing a resin mixed with magnetic powder. And an insulating layer is formed by coating the inner wall of the sensor housing 51 with a resin or the like. Moreover, it may be that the sensor housing 51 is formed of a resin and a magnetic coating is applied to the outer wall of the sensor housing 51.

[0063] As the electrically insulating material having a magnetic effect, for example, high-performance soft magnetic powders (DAPM3, DAPMS7, DAPMSA10, DAPMSC, etc.) manufactured by Daido Steel Co., Ltd., metal glass magnetic powder (SAP-2D) and metal soft magnetic powder (FSC2K) manufactured by Shinto Industries Co., Ltd., and metal-based soft magnetic materials (metal flat powder, metal-based injection molding materials, magnetic sheets) manufactured by MATE Co., Ltd. can be applied.

[0064] And, as Figure 4B shown, a sensor circuit 52 and lead-out electrodes 522 led out from the sensor circuit 52 are arranged in the sensor housing 51. The lead-out electrodes 522 are manufactured by laying a copper foil (having an insulating layer on the sensor housing 51 side) on the sensor housing 51.

[0065] As Figure 4A , Figure 4BAs shown, a through-hole 511 through which one arm of the first clip 53 passes is provided in the sensor housing 51.

[0066] As Figure 4A shown, the first clip 53 can be separated from the sensor housing 51 in its initial state. Further, with the two arms of the first clip 53 slightly opened, one arm is passed through the through-hole 511, and the other arm of the first clip 53 is brought into contact with the unit lead plate. Thereby, the first clip 53 simultaneously clamps the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114), the intermediate bus bar 4, the sensor housing 51, and the lead-out electrode 522 by the elastic force in the direction of closing the arms.

[0067] Thereby, the sensor housing 51 is fixed to the intermediate bus bar 4 by the first clip 53. Further, the lead-out electrode 522 of the sensor circuit 52 is electrically connected to the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114) by the first clip 53.

[0068] In addition, the first clip 53 can be directly joined to the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114) by, for example, ultrasonic welding. Thereby, the sensor circuit 52 can avoid detecting the resistance component of the bus bar.

[0069] In addition, the sensor circuit 52 can be set to any shape, but for example, it is also preferable to connect two rigid substrates 52a and 52b using a flexible substrate 52c and configure them in an L-shape as Figure 4B shown. Alternatively, the lead-out electrode 522 can also be arranged on a flexible substrate connected to the substrate 52a or 52b, and this substrate can be arranged at a position opposite to the through-hole 511.

[0070] Four (only one is shown in Figure 4A ) jumper wires 54 connected to the sensor circuit 52 extend from the side surface of the sensor housing 51, and a fourth clip 542 (a structure similar to that of the first clip 53 can be applied) is mounted at the tip of the jumper wire 54. The fourth clip 542 clamps each bus bar, for example, at the position of the positive unit lead plate 113 (P1) of the battery unit 11 (S1) arranged on the positive bus bar 2, at the position of the positive unit lead plate 113 (P2) of the battery unit 11 (S2) arranged on the positive bus bar 2, at the position of the negative unit lead plate 114 (N3) of the battery unit 11 (S3) arranged on the negative bus bar 3, and at the position of the negative unit lead plate 114 (N4) of the battery unit 11 (S4) arranged on the negative bus bar 3. Thereby, the sensor circuit 52 is electrically connected to each unit lead plate (the positive unit lead plate 113 and the negative unit lead plate 114) via the jumper wire 54 (the fourth clip 542).

[0071] [Connection state of sensor unit 5]

[0072] Figure 5 It is a cross-sectional view showing the connection state of the sensor unit 5. Figure 6 It is Figure 5 a partial detailed view of. As Figure 5 shown, when the terminal cover 7 is installed on the stacking unit 1, each external terminal (the negative external terminal N in the figure) is arranged in the through-hole 71 of the terminal cover 7.

[0073] In addition, the first connection terminal 521 arranged on the sensor housing 51 contacts the second wiring 73, and the second wiring 73 contacts the third wiring 131. In addition, at this time, although not shown in the figure, the second connection terminal 622 arranged on the circuit housing 61 contacts the first wiring 72.

[0074] The first clip 53 penetrates one of the arms through the through-hole 511 formed in the sensor housing 51 as described above, and at the same time clamps the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114), the intermediate bus bar 4, the sensor housing 51, and the lead-out electrode 522. At this time, there is a possibility that the first clip 53 contacts the bus bar. In the case of contact with the bus bar, the charge and discharge current also flows to the first clip 53, and an excessive current flows to the first clip 53 that is not designed for large current flow, and there remains a possibility of heat generation and damage to the first clip 53. Or the resistance component of the bus bar is included in the detection signal input to the sensor circuit 52, resulting in a sensor error.

[0075] Therefore, an insulating layer 531 is arranged on the inner wall of the portion of the first clip 53 exposed from the sensor housing 51 and in the region other than the contact positions with the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114). For the insulating layer 531, an electrical insulating layer can be realized by pasting an electrical insulating tape such as polyimide or resin coating. Thus, electrical insulation between the first clip 53 and the bus bar can be ensured.

[0076] In addition, although not shown in the figure, the inner wall of the through-hole 511 is also covered with an insulating layer. Thus, electrical insulation between the sensor housing 51 and the first clip 53 can also be ensured.

[0077] In addition, when the sensor unit 5 is installed on the intermediate bus bar 4, the first clip 53 can be pre-bonded to the lead-out electrode 522 by soldering or the like. In addition, by applying the horn of ultrasonic vibration (not shown) from the side of the first clip 53 to the contact position between the first clip 53 and the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114) Figure 6Press (arrow as shown) to fuse the first clip 53, the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114), and the intermediate bus bar 4 together. Thus, the first clip 53 can be connected to the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114), and the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114) can be connected to the intermediate bus bar 4. By directly connecting the first clip 53 to the unit lead plates (the positive unit lead plate 113 and the negative unit lead plate 114) without contacting the intermediate bus bar 4 in this way, the state of the battery cell 11 can be detected with high precision without detecting the resistance component of the bus bar. The above connection form can also be similarly applied to the sub-circuit part 6.

[0078] [Circuit diagram]

[0079] Figure 7 is a circuit diagram of the sensor unit 5, the battery cell 11, the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4. As Figure 7 shown, the battery cells 11 (S1) and 11 (S2) are connected in parallel between the positive bus bar 2 and the intermediate bus bar 4.

[0080] The positive side (positive unit lead plate 113) of the battery cell 11 (S1) has a contact (P1) closest to the positive external terminal P at the positive bus bar 2, and the negative side (negative unit lead plate 114) has a contact (N1) closest to the intermediate external terminal M at the intermediate bus bar 4.

[0081] The positive side (positive unit lead plate 113) of the battery cell 11 (S2) has a contact (P2) farthest from the positive external terminal P at the positive bus bar 2, and the negative side (negative unit lead plate 114) has a contact (N2) second closest to the intermediate external terminal M at the intermediate bus bar 4.

[0082] The battery cells 11 (S3) and 11 (S3) are connected in parallel between the intermediate bus bar 4 and the negative bus bar 3.

[0083] The positive side (positive unit lead plate 113) of the battery cell 11 (S3) has a contact (P3) third closest to the intermediate external terminal M at the intermediate bus bar 4, and the negative side (negative unit lead plate 114) has a contact (N3) closest to the negative external terminal N at the negative bus bar 3.

[0084] The positive side (positive unit lead plate 113) of the battery cell 11 (S4) has a contact (P4) farthest from the intermediate external terminal M at the intermediate bus bar 4, and the negative side (negative unit lead plate 114) has a contact (N4) farthest from the negative external terminal N at the negative bus bar 3.

[0085] The sensor circuit 52 is connected to the contact (N1), the contact (N2), the contact (P3), and the contact (P4) respectively by using the first clip 53 attached to the sensor housing 51.

[0086] In addition, the sensor circuit 52 is connected to the contact (P1), the contact (P2), the contact (N3), and the contact (N4) respectively by using the jumper 54 (the fourth clip 542).

[0087] Therefore, the sensor circuit 52 can detect the state of the battery cell 11 (S1) from the contact (P1) and the contact (N1), detect the state of the battery cell 11 (S2) from the contact (P2) and the contact (N2), detect the state of the battery cell 11 (S3) from the contact (P3) and the contact (N3), and detect the state of the battery cell 11 (S4) from the contact (P4) and the contact (N4).

[0088] [First Modification Example]

[0089] Figure 8 It is a perspective view of the first modification example of the battery module of the present embodiment. Figure 9A It is a plan view of the sensor power supply unit 6a of the first modification example. Figure 9B It is a cross-sectional view before the sensor power supply unit 6a of the first modification example is sandwiched between the positive bus bar 2 and the negative bus bar 3. Figure 9C It is a cross-sectional view after the sensor power supply unit 6a of the first modification example is sandwiched between the positive bus bar 2 and the negative bus bar 3. Figure 9D It is a cross-sectional view when the sensor power supply unit 6a of the first modification example is fixed by using clips (the second clip 63, the third clip 64). Figure 10 It is a circuit diagram of the sensor unit 5, the battery cell 11, the positive bus bar 2, the negative bus bar 3, the intermediate bus bar 4, and the sensor power supply unit 6a of the first modification example. In addition, Figure 8 the illustration of the sensor unit 5 and the terminal cover 7 is omitted.

[0090] When the voltage of the battery cell 11 changes due to the state of charge (SOC) and the voltage measurement (AD conversion) value in the sensor circuit 52 is given a variation, the sensor power supply unit 6a can be used to eliminate this variation.

[0091] The sensor power supply unit 6a includes: an insulating holding member 61a, which is sandwiched between the positive bus bar 2 and the negative bus bar 3; a sensor power supply circuit 62a ( Figure 9A ), which is mounted on the holding member 61a; a first lead electrode 623 ( Figure 9A ), which is electrically connected to the positive electrode side of the sensor power supply circuit 62a; a second lead electrode 624 ( Figure 9A), which is electrically connected to the negative electrode side of the sensor power supply circuit 62a; a second connection terminal 622, which is connected to the output side of the sensor power supply circuit 62a; a second clip 63; and a third clip 64.

[0092] The holding member 61a is shaped like an L when viewed in plan on the side that contacts the negative electrode bus bar 3 as shown, but has a Japanese U-shaped cross-section when viewed from the cross-sectional direction (the thickness direction of the laminated unit 1). Figure 9A as shown, and has a Japanese U-shaped cross-section when viewed from the cross-sectional direction (the thickness direction of the laminated unit 1) as shown. Figure 9B as shown.

[0093] The sensor power supply circuit 62a is, for example, a portion extending in the thickness direction of the holding member 61a and is disposed on the back surface of the opposite surface of the terminal cover 7 ( Figure 3 ). The sensor power supply circuit 62a is connected to the positive terminal and the negative terminal and efficiently takes in the voltage of two series connections (2.5 - 4.2 V × 2) as input. Therefore, by mounting the sensor power supply circuit 62a at a position where it can be connected to the positive electrode bus bar 2 and the negative electrode bus bar 3 at the shortest distance, the lengths of the leaf spring-shaped second clip 63 and third clip 64 as connection members (substitute for wiring) can be shortened, which is advantageous in terms of rigidity during fitting and cost savings of materials.

[0094] Regarding the battery module shown in Figure 8 , the specification is such that the negative electrode bus bar 3 approaches the upper space of the positive electrode bus bar 2. Therefore, if the sensor power supply circuit 62a is mounted in this upper space (the second divided space 143 ( Figure 2 , Figure 9B ), it is possible to shorten the lengths of the second clip 63 and the third clip 64, which is preferable.

[0095] Furthermore, in the connection of the sensor power supply circuit 62a, the influence of the bus bar resistance on the sensing detection can be ignored. Therefore, the connection points of the second clip 63 and the third clip 64 can be either the bus bar or the unit lead plate.

[0096] Moreover, when the upper surface of the holding member 61a contacts the inner wall (thin plate portion 12) or the stopper 141 of the storage space 14, the holding member 61a can be fixed using, for example, an elastic sheet, double-sided tape, a modified silicone adhesive, etc. This is also an effective fixing method for ensuring vibration resistance during vehicle mounting.

[0097] The connection form between the second connection terminal 622 and the first connection terminal 521 ( Figure 3 ) is the same as the form shown in Figure 3 , but as shown in Figure 10As shown, the first connection terminal 521 and the second connection terminal 622 may also be omitted, and the power output terminal (OUT) of the sensor power supply circuit 62a and the power input terminal (IN) of the sensor circuit 52 may be directly connected using a jumper wire 65.

[0098] The first lead electrode 623 is disposed on the back surface of the contact surface between the holding member 61a and the positive bus bar 2.

[0099] The second lead electrode 624 is disposed on the back surface of the contact surface between the holding member 61a and the negative bus bar 3 and is a portion that narrows in the lateral direction with a width of Figure 9A .

[0100] A through hole 66 is disposed on the side of the first lead electrode 623 of the portion of the holding member 61a that extends in the thickness direction, and the first lead electrode 623 is disposed at a position opposite to the through hole 66.

[0101] As the mounting sequence of the sensor power supply unit 6a, as Figure 9B and Figure 9C shown, the holding member 61a is sandwiched between the positive bus bar 2 and the negative bus bar 3. And, as Figure 9C and Figure 9D shown, one arm of the second clip 63 penetrates through the through hole 66 and contacts the first lead electrode 623, and the other arm of the second clip 63 contacts the positive bus bar 2, so that the positive bus bar 2, the holding member 61a (on the positive bus bar 2 side), and the first lead electrode 623 are simultaneously clamped by the second clip 63. Similarly, as Figure 9C and Figure 9D shown, one arm of the third clip 64 contacts the second lead electrode 624, and the other arm of the third clip 64 contacts the negative bus bar 3, so that the negative bus bar 3, the holding member 61a (on the negative bus bar 3 side), and the second lead electrode 624 are simultaneously clamped by the third clip 64.

[0102] Using the above sequence, the holding member 61a (on the positive bus bar 2 side) is fixed to the positive bus bar 2, and the first lead electrode 623 is electrically connected to the positive bus bar 2 (contact point (P2)) by means of the second clip 63 ( Figure 10 ). In addition, the holding member 61a (on the negative bus bar 3 side) is fixed to the negative bus bar 3, and the second lead electrode 624 is electrically connected to the negative bus bar 3 (contact point (N4)) by means of the third clip 64 ( Figure 10 ).

[0103] In addition, when the gap between the negative electrode bus bar 3 and the inner wall of the accommodation space 14 is narrow and the third clip 64 simultaneously clamps the second lead electrode 624, the holding member 61a, and the negative electrode bus bar 3 (unit lead plate), there is a case where the third clip 64 interferes with the inner wall of the accommodation space 14 and it is difficult to clamp. In this case, a lead plate (not shown) extending from the second lead electrode 624 is disposed on the negative electrode bus bar 3, and the third clip 64 clamps the lead plate (not shown) and the negative electrode bus bar 3 (unit lead plate). Thereby, the width between the lead plate (not shown) and the inner wall of the accommodation space 14 is widened by an amount corresponding to the thickness of the holding member 61a not being present, and thus, the clamping of the third clip 64 can be easily performed.

[0104] [Jumper, Clip]

[0105] Figure 11 FIG. is an example showing a jumper 54 extending from the sensor unit 5. Figure 12 FIG. is an example showing a clip (first clip 53) attached to the sensor housing 51.

[0106] As Figure 11 shown, the jumper 54 includes a coated wiring 541 that deforms flexibly and a fourth clip 542 disposed at the tip of the coated wiring 541. The fourth clip 542 is connected to a conduction wire (copper wire) inside the coated wiring 541. In addition, the fourth clip 542 is set such that the width between the two arms is slightly smaller than the dimension obtained by adding the thickness of the bus bar and the thickness of the unit lead plate, and the bus bar and the unit lead plate can be simultaneously clamped between the two arms.

[0107] As Figure 12 shown, the first clip 53 has a structure in which arms 533, 534 extend from both ends in the width direction of the base 532. The pair of arms 533, 534 are set to have a shape in which the interval between them becomes narrower as they move away from the base 532 and then becomes wider midway. In the arm 533, the portion where the interval from the arm 534 is the narrowest is the portion that applies a pressing force to the unit lead plate (positive electrode unit lead plate 113, negative electrode unit lead plate 114) ( Figure 6 ).

[0108] In addition, a flat portion 535 is formed at the center of the arm 534 that contacts the lead electrode 522 ( Figure 5 , Figure 6 ) and is disposed so as to stand substantially perpendicular to the base 532. Therefore, when the first clip 53 is attached to the sensor housing 51, the flat portion 535 makes surface contact with the lead electrode 522, and thus, the contact resistance between the lead electrode 522 ( Figure 5 , Figure 6 ) and the first clip 53 can be reduced.

[0109] [Second Modified Example]

[0110] Figure 13 This is the second modification of the battery module of the present embodiment, and it is a circuit diagram of the sensor unit 5, the battery cells 11, the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4.

[0111] The second modification has a structure for simply measuring the apparent internal resistance between the positive external terminal P and the intermediate external terminal M (or between the intermediate external terminal M and the negative external terminal N).

[0112] In Figure 13 when the resistance of the positive bus bar 2 from the positive external terminal P to the contact point (P1) is set as Rb, the resistance of the positive bus bar 2 from the contact point (P1) to the contact point (P2) is set as Rb12, the resistance of the intermediate bus bar 4 from the intermediate external terminal M to the contact point (N1) is set as Rb, the resistance of the intermediate bus bar 4 from the contact point (N1) to the contact point (N2) is set as Rb12, the internal resistance of the battery cell 11 (S1) is set as Rc1, and the internal resistance of the battery cell 11 (S2) is set as Rc2, the apparent internal resistance Rpm between the positive external terminal P and the intermediate external terminal M is represented by the following formula (1).

[0113] [Equation 1]

[0114]

[0115] The resistance of the bus bar is sufficiently small compared to the internal resistance Rc1 of the battery cell 11 (S1) and the internal resistance Rc2 of the battery cell 11 (S2). Therefore, it can be regarded that Rb12 << Rc2, and in formula (1), it can be regarded that Rb12 = 0 and Rc2 = Rc1. Thus, formula (1) can be simplified to the following formula (2).

[0116] [Equation 2]

[0117]

[0118] Therefore, even if the internal resistance of the battery cells 11 connected in parallel is configured to be detected in the same way as when one cell is connected, it is practical.

[0119] In addition, on the premise that Rc1 = Rc = 2, strictly speaking, due to the difference in the bus bar resistance, more charge and discharge current flows to the battery cell 11 (S1) closer to the positive external terminal P and the intermediate external terminal M. Therefore, from the viewpoint of diagnosing the degree of battery deterioration (health condition, SOH: State Of Health), it is appropriate to connect the sensor circuit 52 to the battery cell 11 (S1) through which more charge and discharge current flows among the battery cell 11 (S1) and the battery cell 11 (S2).

[0120] Therefore, by detecting the internal resistance Rc1 of the battery cell 11 (S1) using the sensor circuit 52 and applying the internal resistance Rc1 to Equation (2), the combined resistance between the battery cell 11 (S2), that is, the internal resistance Rpm between the positive electrode external terminal P and the intermediate external terminal M, can be calculated.

[0121] Although the above description has been given taking the battery cells 11 (S1) and 11 (S2) as examples, it is also applicable when calculating the internal resistances of the battery cells 11 (S3) and 11 (S4) as observed from the intermediate external terminal M and the negative electrode external terminal N. That is, by detecting the internal resistance of the battery cell 11 (S3) using the sensor circuit 52 and applying the internal resistance to Equation (2), the combined resistance between the battery cell 11 (S4), that is, the internal resistance between the intermediate external terminal M and the negative electrode external terminal N, can be calculated.

[0122] [Effects of the Present Embodiment]

[0123] The battery module according to the present embodiment includes: a stacking unit 1 formed by stacking a plurality of battery cells 11; bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4) connected to the battery cells 11; and a sensor unit 5 electrically connected to the bus bars and including a sensor circuit 52 for measuring the state of the battery cells. In this battery module, the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4) are arranged in a storage space 14 formed on one side surface of the stacking unit 1. The sensor unit 5 includes: a sensor housing 51 that houses the sensor circuit 52 and is formed in a shape similar to that of the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4) and is housed in the storage space 14 so as to be in contact with the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4); and a fitting portion (first clip 53) that is electrically connected to the sensor circuit 52 and is arranged at a position opposite to the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4) in the sensor housing 51 when the sensor housing 51 is housed in the storage space 14 and can be fitted to the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4). By fitting the fitting portion (first clip 53) to the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4), the sensor housing 51 is fixed to the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4), and the sensor circuit 52 is electrically connected to the bus bars (positive electrode bus bar 2, negative electrode bus bar 3, intermediate bus bar 4) via the fitting portion (first clip 53).

[0124] According to the above structure, by integrating the sensor housing 51 and the fitting portion (the first clip 53) that serves as a terminal electrically connected to the sensor circuit 52, and directly connecting the fitting portion (the first clip 53) to the bus bars (the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4), it is possible to build the battery module without increasing the external dimensions of the battery module, while reducing the wiring material and the working hours at the same time. In addition, by utilizing the accommodation space 14 that inevitably occurs in the structure of the bus bars (the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4), the sensor unit 5 can be installed without increasing the thickness direction of the battery module. Moreover, the wiring length can be minimized or omitted as much as possible, so it is easy to take countermeasures to prevent short circuits during assembly. In addition, the same effect can also be obtained in the disassembly operation of the reuse or recycling process. Based on the above content, an overall comprehensive cost reduction effect can be obtained from the manufacturing to the disposal of the battery.

[0125] However, it is configured to apply a predetermined surface pressure to the battery cell 11. This is caused by a structure that restricts the volume expansion resulting from the reduction and deterioration of the inter-electrode resistance. Therefore, the space (gap) in the stacking direction of the battery cell 11 is set to the minimum required.

[0126] Correspondingly, the sensor circuit 52 installed on the outer surface of the battery cell 11 is required to be made small and thin. Along with this, the degree of freedom in the selection of components and manufacturing methods is restricted, and the manufacturing cost becomes expensive.

[0127] On the other hand, there is at least a space corresponding to the thickness of the stacking unit 1 in the installation area of the bus bars (the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4). As long as it can be accommodated in this space, the cost can be reduced due to the increased degree of freedom in design and the selection of components.

[0128] In addition, in terms of EIS (Electrochemical Impedance Spectroscopy) measurement (internal resistance measurement), which is a means of knowing the internal state of the battery cell 11, precise four-terminal connection corresponding to its measurement range (the level of the internal resistance of the battery cell 11) is required. Therefore, in the past (refer to Patent Document 1), separate wiring was performed on the unit lead plate of the battery cell 11.

[0129] In addition, in order to reduce power loss, the bus bars (positive bus bar 2, negative bus bar 3, intermediate bus bar 4) are designed to connect the battery cells 11 with the shortest distance. Therefore, in this embodiment, by integrating and installing a connector (first clip 53) having a contact point near the connection point between the bus bar (positive bus bar 2, negative bus bar 3, intermediate bus bar 4) and the unit lead plate with the sensor housing 51 (sensor circuit 52), it is possible to achieve the same precise measurement as in the case where the signal connection of the sensor circuit 52 is separately wired and connected to the unit lead plate. Thus, the measurement accuracy is maintained, and at the same time, the fixing / wiring operation of the sensor circuit 52 is completed in one process. In addition, without using an adhesive for wiring fixation of the sensor circuit 52, it is effective in cost reduction, environmental protection, and resource saving.

[0130] In addition, power is not supplied to the sensor circuit 52 until the sensor housing 51 is installed on the bus bar (positive bus bar 2, negative bus bar 3, intermediate bus bar 4). Also, power supply to the sensor circuit 52 is blocked by disassembling the sensor housing 51. Therefore, it is possible to prevent a short circuit (external short circuit of the battery cell 11) between the positive and negative electrodes of the battery cell 11 via the sensor circuit 52 when the sensor housing 51 is disassembled and assembled.

[0131] After the sensor circuit 52 is newly manufactured, it can continuously function until the unit life is reached. Therefore, charge and discharge control (deterioration suppression) based on the history of the battery cell 11 can be performed. As a result, a reduction in the comprehensive cost caused by using up the capacity of the battery cell 11 can be achieved.

[0132] In this embodiment, the sensor circuit 52 includes a plurality of divided sensor circuits (sensor circuit 52), the sensor housing 51 includes a plurality of divided sensor housings (sensor housing 51) that respectively accommodate the divided sensor circuits 52, and the divided sensor housings (sensor housing 51) are arranged in the accommodation space 14.

[0133] According to the above structure, even when the accommodation space 14 is divided finely by the bus bar (positive bus bar 2, negative bus bar 3, intermediate bus bar 4), the sensor unit 5 (sensor circuit 52) is divided into a plurality of parts, and the same number of divided sensor housings (sensor housing 51) as the number of the sensor unit 5 is prepared. The divided sensor circuits (sensor circuit 52) are accommodated in each divided sensor housing (sensor housing 51) and are respectively arranged in the accommodation space 14. Thus, a plurality of divided sensor housings (sensor housing 51) with small sizes are arranged in the accommodation space 14. Therefore, they can be arranged without interfering with the bus bar, and the design freedom of the battery module can be improved.

[0134] In the present embodiment, the bus bars (positive bus bar 2, negative bus bar 3, intermediate bus bar 4) include a positive bus bar 2, a negative bus bar 3, and an intermediate bus bar 4. The battery cells 11 include a first battery cell (battery cells 11(S1), battery cells 11(S2)) that electrically connects the positive bus bar 2 and the intermediate bus bar 4, and a second battery cell (battery cells 11(S3), battery cells 11(S4)) that electrically connects the intermediate bus bar 4 and the negative bus bar 3. The sensor housing 51 is formed to be similar in shape to the intermediate bus bar 4, and a plurality of fitting portions (first clips 53) are arranged so as to face the connection positions between the intermediate bus bar 4 and the first battery cell (battery cells 11(S1), battery cells 11(S2)) and the connection positions between the intermediate bus bar 4 and the second battery cell (battery cells 11(S3), battery cells 11(S4)) respectively when the sensor housing 51 is housed in the housing space 14.

[0135] According to the above structure, by arranging the sensor housing 51 in the space separated by the intermediate bus bar 4 and the inner wall of the housing space 14, where the remaining space in the structure of the battery module is relatively large, it is possible to easily construct the battery module. Among them, the contacts (N1, N2, P3, P4) between the first battery cell (battery cells 11(S1), battery cells 11(S2)) and the second battery cell (battery cells 11(S3), battery cells 11(S4)) are gathered at the intermediate bus bar 4. Therefore, it is possible to shorten the length of the leaf spring-shaped contact electrode, which is a connecting component (substitute for wiring) between the sensor circuit 52 and the unit lead plate (which is advantageous in terms of rigidity during fitting and cost savings of materials). In addition, due to the support and fixation of the sensor circuit 52 at multiple points (4 points in the present embodiment), the anti-vibration design is also advantageous (the strength required for fixing the sensor circuit 52 and the degree of freedom in the design of the support points can be obtained). Moreover, the lower surface of the sensor housing 51 may be in contact with the thin plate portion 12 or the stopper 141 and fixed using, for example, an elastic sheet, double-sided tape, modified silicone adhesive, etc. This is also an effective fixing method for having anti-vibration performance during vehicle mounting.

[0136] In the present embodiment, the fitting portion (first clip 53) has a clip shape that simultaneously clamps the sensor housing 51 and the bus bars (positive bus bar 2, negative bus bar 3, intermediate bus bar 4).

[0137] According to the above structure, disassembly and assembly are easy, and the present embodiment can be realized at low cost. In addition, the electrical connection points are easy to manage. Therefore, by excluding resistance components such as the bus bars (positive bus bar 2, negative bus bar 3, intermediate bus bar 4) that have no relation to the internal state (internal resistance) of the battery cell 11 from the sensing detection object, precise state detection (monitoring) of the inside of the battery cell 11 can be performed.

[0138] In the present embodiment, the sensor housing 51 is formed of an electrically insulating material having a magnetic effect.

[0139] According to the above structure, the inside of the sensor housing 51 is electrostatically shielded from the outside. Therefore, even if the sensor circuit 52 is arranged near the bus bar, the electromagnetic induction noise with respect to the sensor circuit 52 can be reduced.

[0140] In the present embodiment, the positive bus bar 2 includes a positive external terminal P connected to the outside, the negative bus bar 3 includes a negative external terminal N connected to the outside, a plurality of first battery units (battery unit 11(S1), battery unit 11(S2)) are connected in parallel between the positive bus bar 2 and the intermediate bus bar 4, a plurality of second battery units (battery unit 11(S3), battery unit 11(S4)) are connected in parallel between the intermediate bus bar 4 and the negative bus bar 3, and the fitting portion (the first clip 53) is arranged so as to face the following connection positions respectively when the sensor housing 51 is received in the receiving space 14: the connection position (contact point (N1)) between the first battery unit (battery unit 11(S1)) and the intermediate bus bar 4 in the sensor housing 51; the connection position (contact point (P3)) between the second battery unit (battery unit 11(S3)) and the intermediate bus bar 4 in the sensor housing 51, wherein the first battery unit (battery unit 11(S1)) is connected to the positive external terminal P at the position closest to the positive external terminal P electrically among the first battery units (battery unit 11(S1), battery unit 11(S2)), and the second battery unit (battery unit 11(S3)) is connected to the negative external terminal N at the position closest to the negative external terminal N electrically among the second battery units (battery unit 11(S3), battery unit 11(S4)).

[0141] According to the above structure, even if the number of connection points with the battery unit 11 is omitted, the internal state of the battery unit 11 that is practically effective can be detected. Therefore, the state of the battery unit 11 can be detected more easily and inexpensively.

[0142] In the present embodiment, the battery unit 11 includes: a power storage portion 111; and lead plate units (a positive electrode unit lead plate 113, a negative electrode unit lead plate 114) that extend from the power storage portion 111 and are connected to bus bars (the positive bus bar 2, the negative bus bar 3, the intermediate bus bar 4), and the fitting portion (the first clip 53) is fitted to the bus bars (the positive bus bar 2, the negative bus bar 3, the intermediate bus bar 4) in a form that clamps the lead plate units (the positive electrode unit lead plate 113, the negative electrode unit lead plate 114) together with the bus bars (the positive bus bar 2, the negative bus bar 3, the intermediate bus bar 4).

[0143] According to the above structure, the fitting part (the first clip 53) is not in contact with the bus bars (the positive bus bar 2, the negative bus bar 3, and the intermediate bus bar 4). Therefore, the sensor circuit 52 does not sense the resistance component of the bus bar and can detect the state of the battery cell 11 with high precision.

[0144] In the present embodiment, there is further provided: a cover (terminal cover 7) that is inserted into the stacking unit 1 so as to cover the accommodation space 14; a wiring (fourth wiring 74) that is disposed on the inner wall of the cover (terminal cover 7); and a power supply unit (sensor power supply unit 6a) that includes a power supply circuit (sensor power supply circuit 62a) for supplying power to the sensor unit 5. In the accommodation space 14, a plurality of divided spaces are formed by bus bars (positive bus bar 2, negative bus bar 3, intermediate bus bar 4). The sensor unit 5 is accommodated in the first divided space 142 formed by the intermediate bus bar 4 among the divided spaces. A power supply input terminal (first connection terminal 521) electrically connected to the sensor circuit 52 is disposed on the surface of the sensor housing 51 facing the cover (terminal cover 7). The power supply unit (sensor power supply unit 6a) includes: a holder 61a on which the power supply circuit (sensor power supply circuit 62a) is mounted and which is accommodated in the second divided space 143 formed between the positive bus bar 2 and the negative bus bar 3 among the divided spaces; a second fitting portion (second clip 63) that is electrically connected to the input side (positive side) of the power supply circuit (sensor power supply circuit 62a) and that is disposed at a position of the holder 61a facing the positive bus bar 2 when the holder 61a is accommodated in the second divided space 143 and can be fitted with the positive bus bar 2; a third fitting portion (third clip 64) that is electrically connected to the input side (negative side) of the power supply circuit (sensor power supply circuit 62a) and that is disposed at a position of the holder 61a facing the negative bus bar 3 when the holder 61a is accommodated in the second divided space 143 and can be fitted with the negative bus bar 3; and a power supply output terminal (second connection terminal 622) that is electrically connected to the output side of the power supply circuit (sensor power supply circuit 62a) and that is disposed at a position of the holder 61a facing the cover (terminal cover 7). By fitting the second fitting portion (second clip 63) with the positive bus bar 2, the holder 61a is fixed to the positive bus bar 2, and the power supply circuit (sensor power supply circuit 62a) is electrically connected to the positive bus bar 2 by means of the second fitting portion (second clip 63). By fitting the third fitting portion (third clip 64) with the negative bus bar 3, the holder 61a is fixed to the negative bus bar 3, and the power supply circuit (sensor power supply circuit 62a) is electrically connected to the negative bus bar 3 by means of the third fitting portion (third clip 64). By inserting the cover (terminal cover 7) into the stacking unit 1, the wiring (fourth wiring 74) comes into contact with the power supply output terminal (second connection terminal 622) and the power supply input terminal (first connection terminal 521) simultaneously. The power supply output terminal (second connection terminal 622) is electrically connected to the power supply input terminal (first connection terminal 521) by means of the wiring (fourth wiring 74).

[0145] In addition, in the present embodiment, there is further provided: a cover (terminal cover 7) that is inserted into the stacking unit 1 so as to cover the accommodation space 14; a first wiring 72 and a second wiring 73 that are disposed on the inner wall of the cover (terminal cover 7); a third wiring 131 that is disposed on the outer wall of the accommodation space 14 that contacts the cover (terminal cover 7); and a power supply unit (sensor power supply unit 6a) that includes a power supply circuit (sensor power supply circuit 62a) that supplies power to the sensor unit 5. In the accommodation space 14, a plurality of divided spaces are formed by bus bars (positive bus bar 2, negative bus bar 3, intermediate bus bar 4). The sensor unit 5 is accommodated in a first divided space 142 formed by the intermediate bus bar 4 among the divided spaces. A power input terminal (first connection terminal 521) electrically connected to the sensor circuit 52 is disposed on the surface of the sensor housing 51 that faces the cover (terminal cover 7). The power supply unit (sensor power supply unit 6a) includes: a holder 61a on which the power supply circuit (sensor power supply circuit 62a) is mounted and that is accommodated in a second divided space 143 formed between the positive bus bar 2 and the negative bus bar 3 among the divided spaces; a second fitting portion (second clip 63) that is electrically connected to the input side (positive side) of the power supply circuit (sensor power supply circuit 62a) and that is disposed at a position of the holder 61a facing the positive bus bar 2 when the holder 61a is accommodated in the second divided space 143 and can be fitted with the positive bus bar 2; a third fitting portion (third clip 64) that is electrically connected to the input side (negative side) of the power supply circuit (sensor power supply circuit 62a) and that is disposed at a position of the holder 61a facing the negative bus bar 3 when the holder 61a is accommodated in the second divided space 143 and can be fitted with the negative bus bar 3; and a power output terminal (second connection terminal 622) that is electrically connected to the output side of the power supply circuit (sensor power supply circuit 62a) and that is disposed at a position of the holder 61a facing the cover (terminal cover 7). By fitting the second fitting portion (second clip 63) with the positive bus bar 2, the holder 61a is fixed to the positive bus bar 2, and the power supply circuit (sensor power supply circuit 62a) is electrically connected to the positive bus bar 2 by means of the second fitting portion (second clip 63). By fitting the third fitting portion (third clip 64) with the negative bus bar 3, the holder 61a is fixed to the negative bus bar 3, and the power supply circuit (sensor power supply circuit 62a) is electrically connected to the negative bus bar 3 by means of the third fitting portion (third clip 64). By inserting the cover (terminal cover 7) into the stacking unit 1, the first wiring 72 comes into contact with the power output terminal (second connection terminal 622) and the third wiring 131 simultaneously, and the second wiring 73 comes into contact with the power input terminal (first connection terminal 521) and the third wiring 131 simultaneously. Thus, the power output terminal (second connection terminal 622) is electrically connected to the power input terminal (first connection terminal 521) by means of the first wiring 72, the second wiring 73, and the third wiring 131.

[0146] According to the above structure, power is not supplied to the power circuit (sensor power circuit 62a) until the power supply unit (sensor power supply unit 6a) is installed on the positive bus bar 2 and the negative bus bar 3. In addition, power supply to the power circuit (sensor power circuit 62a) is blocked by removing the power supply unit (sensor power supply unit 6a) from the positive bus bar 2 or the negative bus bar 3. Therefore, it is possible to prevent a short circuit (external short circuit of the battery unit 11) between the positive and negative electrodes of the battery unit 11 via the power circuit (sensor power circuit 62a) when the power circuit (sensor power circuit 62a) is disassembled and assembled.

[0147] In addition, according to the above structure, power is not supplied to the sensor circuit 52 until the cover (terminal cover 7) is installed on the stacking unit 1. In addition, power supply to the sensor circuit 52 is blocked by removing the cover (terminal cover 7) from the stacking unit 1. Therefore, it is possible to prevent a short circuit (external short circuit of the battery unit 11) between the positive and negative electrodes of the battery unit 11 via the cover (terminal cover 7) having wirings (first wiring 72 and second wiring 73, or fourth wiring 74) when the cover (terminal cover 7) is disassembled and assembled.

[0148] In the present embodiment, the stacking unit 1 has a pair of fastening portions 112 that fasten a plurality of battery units 11 into an integral body, and the fastening portions 112 are disposed at least at both ends of one side surface of the stacking unit 1, and the storage space 14 is disposed between the pair of fastening portions 112.

[0149] According to the above structure, since the storage space 14 is disposed in an existing space inside the outer shape of the stacking unit 1, it is possible to protect the sensor unit 5 and the like disposed in the storage space 14.

[0150] The embodiments of the present invention have been described above. The above embodiments merely represent a part of the application examples of the present invention, and the gist is not to limit the protection scope of the present invention to the specific structures of the above embodiments. In addition, the above embodiments can be appropriately combined.

[0151] This application claims the priority based on Japanese Patent Application No. 2022-085496 filed with the Japan Patent Office on May 25, 2022, and the entire contents of this application are incorporated herein by reference.

Claims

1. A battery module, comprising: A stacking unit formed by stacking a plurality of battery cells; A bus bar connected to the battery cells; and A sensor unit electrically connected to the bus bar and including a sensor circuit for measuring the state of the battery cells, In the battery module, The bus bar is disposed in a storage space formed on one side surface of the stacking unit, The sensor unit Includes: A sensor housing that houses the sensor circuit and is formed in a shape similar to that of the bus bar and is housed in the storage space in a manner of contacting the bus bar; And A fitting portion electrically connected to the sensor circuit and disposed at a position opposite to the bus bar in the sensor housing when the sensor housing is housed in the storage space and capable of fitting with the bus bar, By fitting the fitting portion with the bus bar, the sensor housing is fixed to the bus bar, and the sensor circuit is electrically connected to the bus bar through the fitting portion.

2. The battery module according to claim 1, Wherein, The sensor circuit includes a plurality of divided sensor circuits, the sensor housing includes a plurality of divided sensor housings respectively housing the divided sensor circuits, and the sensor housing is disposed in the storage space.

3. The battery module according to claim 1, Wherein, The bus bar includes a positive bus bar, a negative bus bar, and an intermediate bus bar, The battery cells include: A first battery cell that electrically connects the positive bus bar and the intermediate bus bar; and A second battery cell that electrically connects the intermediate bus bar and the negative bus bar, The sensor housing is formed in a shape similar to that of the intermediate bus bar, The fitting portions are arranged in a plurality of ways such that when the sensor housing is housed in the storage space, they are respectively opposite to the connection position between the intermediate bus bar and the first battery cell and the connection position between the intermediate bus bar and the second battery cell.

4. The battery module according to any one of claims 1 to 3, Wherein, The fitting portion has a clip shape that simultaneously clamps the sensor housing and the bus bar.

5. The battery module according to claim 1, Wherein, The sensor housing is formed of an electrically insulating material having a magnetic effect.

6. The battery module according to claim 3, Wherein, The positive bus bar includes a positive external terminal connected to the outside, The negative bus bar includes a negative external terminal connected to the outside, A plurality of the first battery cells are connected in parallel between the positive bus bar and the intermediate bus bar, A plurality of the second battery cells are connected in parallel between the intermediate bus bar and the negative bus bar, The fitting portion is arranged such that when the sensor housing is received in the receiving space, it faces the following connection positions respectively: the connection position between the first battery unit that connects the positive electrode external terminal at the position in the sensor housing that is electrically closest to the positive electrode external terminal in the first battery unit and the intermediate bus bar; the connection position between the second battery unit that connects the negative electrode external terminal at the position in the sensor housing that is electrically closest to the negative electrode external terminal in the second battery unit and the intermediate bus bar.

7. The battery module according to claim 1, wherein, the battery unit includes: a power storage portion; and a lead plate unit that extends from the power storage portion and is connected to the bus bar, the fitting portion fits with the bus bar in a form that clamps the lead plate unit and the bus bar together.

8. The battery module according to claim 3, wherein, the battery module further includes: a cover that is embedded in the stacking unit so as to cover the receiving space; a first wiring and a second wiring that are arranged on the inner wall of the cover; a third wiring that is arranged on the outer wall of the receiving space that contacts the cover; and a power supply unit that includes a power supply circuit for supplying power to the sensor unit, in the receiving space, a plurality of divided spaces are formed by the bus bar, the sensor unit is received in the first divided space formed by the intermediate bus bar among the divided spaces, a power input terminal electrically connected to the sensor circuit is arranged on the surface of the sensor housing that faces the cover, the power supply unit includes: a holder that mounts the power supply circuit and is received in the second divided space formed between the positive electrode bus bar and the negative electrode bus bar among the divided spaces; a second fitting portion that is electrically connected to the input side of the power supply circuit and is arranged at the position of the holder that faces the positive electrode bus bar when the holder is received in the second divided space and can fit with the positive electrode bus bar; a third fitting portion that is electrically connected to the input side of the power supply circuit and is arranged at the position of the holder that faces the negative electrode bus bar when the holder is received in the second divided space and can fit with the negative electrode bus bar; and a power output terminal that is electrically connected to the output side of the power supply circuit and is arranged at the position of the holder that faces the cover, by fitting the second fitting portion with the positive electrode bus bar, the holder is fixed to the positive electrode bus bar, and the power supply circuit is electrically connected to the positive electrode bus bar through the second fitting portion, by fitting the third fitting portion with the negative electrode bus bar, the holder is fixed to the negative electrode bus bar, and the power supply circuit is electrically connected to the negative electrode bus bar through the third fitting portion. By embedding the cover in the stacking unit, the first wiring contacts the power output terminal and the third wiring simultaneously, and the second wiring contacts the power input terminal and the third wiring simultaneously, so that the power output terminal is electrically connected to the power input terminal via the first wiring, the second wiring, and the third wiring.

9. The battery module according to claim 1, wherein, the stacking unit has a pair of fastening parts for fastening a plurality of the battery cells into an integral body, and the fastening parts are disposed at least at both ends of one side surface of the stacking unit, the accommodation space is disposed between the pair of fastening parts.

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