Battery pack

Abstract

The present invention addresses the problem of providing a battery pack (40) capable of flexibly coping with a specification change, the battery pack (40) mounted in a hybrid system (10) comprising: a battery module (50) for supplying power to a motor generator (2) of the hybrid system (10); a control circuit that controls the battery module (50); and a case (400) accommodating the battery module (50) and the control circuit; a battery module (50) is provided with: a plurality of battery cells (510); and a battery cell case (500) that accommodates the plurality of battery cells (510) and has a fixing part (500a) that is fixed to the case (400). The control circuit has: a BMU85 that monitors and controls the state of the entire battery module (50); and a CMU87 that monitors the state of each of the plurality of battery cells (510) and transmits information to the BMU85. The CMU87 is mounted in a battery cell case (500) in one battery module (50).

Description

Technical Field

[0001] This invention relates to battery packs used in hybrid power systems. Background Technology

[0002] Patent Document 1 discloses a battery mounting structure for electric or hybrid vehicles. This battery mounting structure has a housing on the underside of the floor of the vehicle compartment that houses a plurality of battery modules for vehicle propulsion. The plurality of battery modules are divided into lower and upper modules. The housing has a lower metal housing member, a middle metal housing member, and an upper housing member for covering a defined area of ​​the upper surface of the middle housing member from above. The lower modules are fixed to the bottom of the lower housing member, and the middle housing member is fixed to the lower housing member in a manner that covers the lower modules from above, thereby watertightly housing the lower modules. The upper modules are fixed within a defined area in a state of close contact with the upper surface of the middle housing member. The upper housing member is formed as a container with an opening at the bottom, and is fixed in a state where the periphery of the opening is in close contact with the upper surface of the middle housing member, thereby watertightly housing the upper modules. Furthermore, the box is fixed to the vehicle by installing the lower box component on the underside of the base plate.

[0003] Patent Document 2 discloses a battery pack assembly, for example, for an electric vehicle, comprising multiple stacked batteries. This battery pack assembly has a battery pack body comprising: a first battery group consisting of a plurality of batteries arranged on a single plane; a second battery group overlapping the first battery group with a battery tray, wherein a plurality of identical batteries are arranged on the same plane within the battery tray; a battery section electrically connecting the batteries to each other; and a main housing housing the battery section. The batteries are cuboid in shape and can be arranged in a first posture and a second posture. The first posture is where the height of the second battery group in the stacking direction of the first battery group is smaller, and the second posture is where the position of the terminals in the overlapping direction is higher than the position of the battery terminals in the first posture. The battery pack assembly is characterized in that the first batteries in the first battery group are arranged in the second posture, a hole is formed in the battery tray, and the terminals of the first batteries extend towards the second battery group through the hole; the second batteries in the second battery group are arranged in the first posture near the hole, and the first and second batteries are electrically connected to each other by a connecting member of a fixed shape.

[0004] The battery pack housing contains the number of battery cells required to achieve the desired voltage. The status of each battery cell is monitored by the CMU (Cell Management Unit), and the status of the battery module as a whole, containing multiple battery cells, is monitored by the BMU (Battery Management Unit). Therefore, the design of a battery pack requires control circuitry that corresponds to the number and layout of battery cells needed to achieve the desired voltage specifications, making it difficult to flexibly respond to specification changes.

[0005] Furthermore, the battery pack housing contains the number of battery cells required to achieve the desired voltage. Lithium-ion or nickel-metal hydride batteries are used as these battery cells. The battery cells are configured in a generally cuboid shape, with a plurality of cells arranged within a limited space inside the housing. Since the battery cells generate heat due to the chemical reactions during charging and discharging, it is important to effectively release the heat emitted from the battery cells, which are contained within the housing, to the outside.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2020-001451

[0009] Patent Document 2: Japanese Patent Application Publication No. 2006-080042 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The present invention was made in view of the above circumstances, and its object is to provide a battery pack that can flexibly respond to specification changes. Furthermore, its object is to provide a battery pack that can efficiently release heat from the battery cells to the outside.

[0012] Technical means for solving problems

[0013] A battery pack according to a first aspect of the present invention, mounted in a hybrid power system, comprises: a battery module for supplying power to an electric generator of the hybrid power system; a control circuit for controlling the battery module; and a housing for housing the battery module and the control circuit; the battery module having: a plurality of battery cells; and a battery cell housing for housing the plurality of battery cells; the control circuit having: a BMU (Battery Management Unit) for monitoring and controlling the overall state of the battery pack; and a CMU (Cell Management Unit) for monitoring the state of each of the plurality of battery cells and sending information to the BMU; the CMU being mounted in the battery cell housing within the battery module.

[0014] The second aspect of the present invention provides a battery pack mounted in a hybrid power system, comprising: a battery module for supplying power to an electric generator of the hybrid power system; a control circuit for controlling the battery module; a housing for housing the battery module and the control circuit; and a heat-conducting member disposed between the battery module and the housing, having insulating properties.

[0015] Invention Effects

[0016] According to the present invention, a battery pack capable of flexibly responding to specification changes can be provided. Furthermore, according to the present invention, a battery pack capable of efficiently releasing heat from the battery cells to the outside can be provided. Attached Figure Description

[0017] Figure 1 This is a block diagram representing a hybrid power system.

[0018] Figure 2 This is a perspective view illustrating the appearance of the battery pack according to this embodiment.

[0019] Figure 3 This is a partial exploded perspective view illustrating the battery pack of this embodiment.

[0020] Figure 4 This is a partial exploded 3D view illustrating a battery module.

[0021] Figure 5 This is a schematic three-dimensional diagram illustrating the connection of a plurality of battery cells.

[0022] Figure 6 This is a schematic perspective view illustrating the configuration of multiple battery modules.

[0023] Figure 7 This is a top view illustrating the configuration of multiple battery modules.

[0024] Figure 8 This is a top view illustrating a single battery cell housing.

[0025] Figure 9 This is a top view showing an example of the configuration of a single battery cell housing.

[0026] Figure 10 This is a perspective view showing a configuration example (second example) of a single battery cell housing.

[0027] Figure 11 This is a partial exploded perspective view illustrating another battery pack of this embodiment.

[0028] Figure 12 This is a schematic cross-sectional view illustrating another battery pack in this embodiment.

[0029] Figure 13 This is a perspective view illustrating the top surface of the casing cover. Detailed Implementation

[0030] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0031] Furthermore, the embodiments described below are preferred examples of the present invention, and therefore various technically preferred limitations are attached. However, the scope of the present invention is not limited to these embodiments unless specifically limited in the following description. Additionally, in the accompanying drawings, the same structural members are labeled with the same reference numerals, and detailed descriptions are appropriately omitted.

[0032] (Hybrid power system)

[0033] Figure 1 This is a block diagram representing a hybrid power system.

[0034] The battery pack 40 using the casing of this embodiment is mounted on Figure 1 The hybrid power system 10 shown is a hybrid power system 10. The hybrid power system 10 includes an engine 1, an electric generator 2, and a battery pack 40. The hybrid power system 10 of this embodiment also includes a DC / DC converter 70. The engine 1 is an internal combustion engine, such as a diesel engine. The engine 1 is used, for example, in vehicles (passenger cars, small mobile vehicles, etc.), construction machinery, agricultural machinery, and other industrial machinery.

[0035] Engine 1 is, for example, a turbocharged, high-output three-cylinder, four-cylinder, or other multi-cylinder diesel engine. However, engine 1 is not limited to a diesel engine. Engine 1 has an ECU (Engine Control Unit) 150. The ECU 150 controls the operation of engine 1 and, for example, communicates with the electric generator 2 and the DC / DC converter 70 via CAN (Controller Area Network) to control the electric generator 2 and the DC / DC converter 70.

[0036] When a vehicle equipped with the hybrid power system 10 needs power, such as during start-up or acceleration, the electric generator 2 operates using electricity supplied from the battery pack 40 to assist the engine 1. Additionally, the electric generator 2 uses regenerative braking devices or similar mechanisms to convert the kinetic energy of industrial machinery equipped with the hybrid power system 10 into electrical energy to generate electricity.

[0037] The battery pack 40 includes a battery module 50, a positive-side contactor 75, a negative-side contactor 76, a current detection unit 65, a temperature detection unit 67, a BMU (Battery Management Unit) 85, and a CMU (Cell Management Unit) 87. The battery module 50 serves as the drive power source for the electric generator 2, supplying power to the electric generator 2. The battery module 50 includes at least one battery cell 510. Figure 1 In the hybrid power system 10 shown, the number of battery cells 510 required to obtain a voltage of 48V is included in the battery module 50. Examples of battery cells 510 include lithium-ion batteries (LiB). However, the battery cells 510 in this embodiment are not limited to lithium-ion batteries. The battery module 50 has a positive (+) terminal 51 and a negative (-) terminal 52.

[0038] The positive-side contactor 75 is located in the circuit between the positive terminal 51 of the battery module 50 and the electric generator 2. Specifically, as follows... Figure 1 As shown, the positive-side contactor 75 is disposed on the positive terminal 51 of the battery module 50 and the positive wiring 173, 174 of the electric generator 2. That is, the circuit between the positive terminal 51 of the battery module 50 and the electric generator 2 includes positive wiring 173 and positive wiring 174. The positive-side contactor 75 is electrically connected to the ECU 150 via signal line 181, and opens and closes the positive wiring 173, 174 based on the control signal sent from the ECU 150 via signal line 181.

[0039] Alternatively, the positive-side contactor 75 can also be electrically connected to the BMU85. In this case, the positive-side contactor 75 opens and closes the positive wirings 173 and 174 based on the control signal sent from the BMU85. In the description of this embodiment, the case where the positive-side contactor 75 is electrically connected to the ECU150 via signal line 181 is taken as an example.

[0040] The negative-side contactor 76 is disposed in the circuit between the negative terminal 52 of the battery module 50 and the electric generator 2. Specifically, as follows: Figure 1 As shown, the negative-side contactor 76 is disposed in the negative wiring 175 connecting the negative terminal 52 of the battery module 50 and the electric generator 2. That is, the circuit between the negative terminal 52 of the battery module 50 and the electric generator 2 includes the negative wiring 175. The negative-side contactor 76 is electrically connected to the BMU 85 via signal line 182, and opens and closes the negative wiring 175 based on the control signal sent from the BMU 85 through signal line 182.

[0041] Alternatively, the negative-side contactor 76 can also be electrically connected to the ECU 150. In this case, the negative-side contactor 76 opens and closes the negative wiring 175 based on a control signal sent from the ECU 150. In the description of this embodiment, the case where the negative-side contactor 76 is electrically connected to the BMU 85 via signal line 182 is taken as an example.

[0042] BMU85 is an example of the "control circuit" of the present invention. BMU85 controls the overall voltage of battery module 50. That is, BMU85 is electrically connected to ECU150 via signal line 193, and controls the negative side contactor 76 based on the control signal sent from ECU150 via signal line 193. ECU150 and BMU85 communicate with each other and monitor each other's status, for example, using CAN.

[0043] In addition, the BMU85 can monitor the status of the battery module 50 and detect abnormalities in the battery module 50. For example, the BMU85 can detect overcharge (minor fault) or overcharge (major fault) abnormalities based on the voltage of the battery cell 510 obtained from the CMU87. Alternatively, the BMU85 can detect over-discharge (minor fault) or over-discharge (major fault) abnormalities based on the voltage of the battery cell 510 obtained from the CMU87. Alternatively, the BMU85 can detect over-temperature (minor fault) abnormalities based on the temperature of the battery cell 510 obtained from the CMU87. Alternatively, the BMU85 can detect overcurrent abnormalities based on the current value obtained from the current value detection unit 65 provided on the positive terminal wiring 174.

[0044] CMU87 is an example of the "control circuit" of the present invention. CMU87 monitors the state of the battery cells 510 included in the battery module 50 and sends the information to BMU85. When the battery module 50 includes a plurality of battery cells 510, CMU87 monitors the voltage of each battery cell 510 and sends information related to the voltage of each battery cell 510 to BMU85 via signal line 191. Additionally, CMU87 obtains temperature information of the battery cells 510 detected by the temperature detection unit 67 from signal line 183 and sends information related to the temperature of the battery cells 510 to BMU85 via signal line 191. CMU87 can be installed separately from BMU85 or integrated with BMU85.

[0045] As described above, the negative terminal wiring 175 electrically connects the negative terminal 52 of the battery module 50 to the electric generator 2, becoming ground 100B. For example, the negative terminal wiring 175 is connected to and grounded to the main body of a vehicle equipped with the hybrid power system 10, etc. The positive terminal wiring 173 electrically connects the positive terminal 51 of the battery module 50 to the electric generator 2, and also electrically connects the electric generator 2 to the DC / DC converter 70. Figure 1 As shown in the hybrid power system 10, when the battery module 50 is a 48V lithium-ion battery, the positive terminal wirings 173 and 174 have a potential of 48V relative to the negative terminal wiring 175.

[0046] The DC / DC converter 70 is electrically connected to the battery 80 via positive wiring 171 and negative wiring 172. The battery 80 can be, for example, a 12V lead-acid battery. Negative wiring 172 electrically connects the negative terminal 82 of the battery 80 to the DC / DC converter 70, serving as ground 100B. For example, negative wiring 172 may be connected to and grounded to the main body of a vehicle equipped with a hybrid power system 10. Positive wiring 171 electrically connects the positive terminal 81 of the battery 80 to the DC / DC converter 70. Figure 1 As shown in the hybrid power system 10, when the battery 80 is a 12V lead-acid battery, the positive terminal wiring 171 has a potential of 12V relative to the negative terminal wiring 172.

[0047] As described above, the electric generator 2 uses regenerative braking and the like to convert the kinetic energy of a vehicle equipped with the hybrid power system 10 into electrical energy to generate electricity. Furthermore, the electric generator 2 supplies voltage to the battery module 50 to charge the battery module 50, and supplies voltage to the battery 80 to charge the battery 80. Here, using... Figure 1Taking the hybrid power system 10 shown as an example, the potential of the positive terminal wiring 173 relative to the negative terminal wiring 175 is 48V. That is, the generating voltage of the electric generator 2 is 48V. On the other hand, the potential of the positive terminal wiring 171 relative to the negative terminal wiring 172 is 12V. Therefore, the DC / DC converter 70 converts the 48V voltage generated by the electric generator 2 into a 12V voltage. Thus, the electric generator 2 can supply a 12V voltage to the battery 80 via the DC / DC converter 70 to charge the battery 80.

[0048] Additionally, the DC / DC converter 70 is electrically connected to the battery module 50 and the battery 80, and is capable of charging and discharging between the battery module 50 and the battery 80 based on control signals sent from the ECU 150. For example, the DC / DC converter 70 can discharge the battery module 50 and charge the battery 80 by converting the voltage and allowing a constant current (e.g., 10A) to flow from the battery module 50 to the battery 80. Alternatively, for example, the DC / DC converter 70 can discharge the battery 80 and charge the battery module 50 by converting the voltage and allowing a constant current (e.g., 10A) to flow from the battery 80 to the battery module 50.

[0049] The hybrid power system 10 of this embodiment has the function of safely cutting off the circuit that supplies power from the battery module 50 to the electric generator 2 when the battery module 50 malfunctions or when the hybrid power system 10 is shut down.

[0050] For example, when the ignition switch is turned on, the ECU 150 sends a control signal to the positive-side contactor 75 via signal line 181 and executes the control to close the positive-side contactor 75, thereby electrically connecting the positive wiring 174. Additionally, the BMU 85, based on the control signal sent from the ECU 150 via signal line 193, executes the control to close the negative-side contactor 76, thereby electrically connecting the negative wiring 175. Thus, the battery module 50 can supply power to the electric generator 2.

[0051] On the other hand, for example, when the ignition switch is off, the ECU 150 sends a control signal to the positive side contactor 75 via signal line 181 and executes the control to open the positive side contactor 75, thereby cutting off the power to the positive wiring 174. Additionally, the BMU 85, based on the control signal sent from the ECU 150 via signal line 193, executes the control to open the negative side contactor 76, thereby cutting off the power to the negative wiring 175. This stops the power supply from the battery module 50 to the electric generator 2.

[0052] Additionally, for example, if the BMU85 detects an abnormality in the battery module 50, the ECU150 sends a first cut-off signal R1 to the positive-side contactor 75 via signal line 181 and controls the opening of the positive-side contactor 75, thereby electrically cutting off the positive wiring 174. Furthermore, the BMU85, independently of the control signal sent from the ECU150, sends a second cut-off signal R2 to the negative-side contactor 76 via signal line 182 and controls the opening of the negative-side contactor 76, thereby electrically cutting off the negative wiring 175.

[0053] Alternatively, as described above, ECU150 and BMU85 communicate with each other and monitor each other's status. Therefore, if an abnormality is detected in BMU85, ECU150 sends a first cut-off signal R1 to the positive-side contactor 75 via signal line 181 and controls the opening of the positive-side contactor 75, thereby electrically cutting off the positive wiring 174. On the other hand, if an abnormality is detected in ECU150, BMU85, without relying on the control signal sent from ECU150, sends a second cut-off signal R2 to the negative-side contactor 76 independently via signal line 182 and controls the opening of the negative-side contactor 76, thereby electrically cutting off the negative wiring 175.

[0054] According to the hybrid power system 10 described above, two contactors (positive-side contactor 75 and negative-side contactor 76 in this embodiment) are provided in the circuit that supplies power from the battery module 50 to the generator 2 (positive wiring 173, 174 and negative wiring 175 in this embodiment). The ECU 150 controls the positive-side contactor 75, and the BMU 85 controls the negative-side contactor 76. Therefore, even if the battery module 50 malfunctions or either the ECU 150 or the BMU 85 malfunctions, the hybrid power system 10 of this embodiment can disconnect the circuit that supplies power from the battery module 50 to the generator 2. Thus, the hybrid power system 10 can improve the safety of the battery module 50 supplying power to the generator 2.

[0055] (Battery pack)

[0056] Figure 2 This is a perspective view illustrating the appearance of the battery pack according to this embodiment.

[0057] Figure 3 This is a partial exploded perspective view illustrating the battery pack of this embodiment.

[0058] Figure 3 The diagram shows the battery pack 400 housing cover 420 with the housing cover 420 open.

[0059] The battery pack 40 includes a battery module 50, a control circuit including BMU85 and CMU87, and a housing 400 that houses the battery module 50 and the control circuit. The housing body 410 and the housing cover 420 are formed, for example, by casting an aluminum-containing metal material. A seal (not shown) is provided at the joint between the housing body 410 and the housing cover 420, thereby making the interior of the housing 400 watertight by covering the housing body 410 with the housing cover 420 and fastening it, for example, with screws.

[0060] The battery module 50, housed in the housing 400, has a plurality of battery cells 510. The plurality of battery cells 510 are housed in a battery cell housing 500. The battery cell housing 500 has a fixing part 500a for fixing to the housing 400 when the plurality of battery cells 510 are housed. One battery module 50 may be housed in a single housing 400, or a plurality of battery modules 50 may be housed in a single housing 400.

[0061] exist Figure 2 and Figure 3 In the example shown, two battery modules 50 are housed in a housing 400. For example, in the case of a 48V battery pack 40, in this embodiment, two 24V battery modules 50 are housed in the housing 400 and connected in series. Nine battery cells 510 are housed in the battery cell housing 500 within each battery module 50.

[0062] In this embodiment, a CMU87 is installed in the battery cell housing 500 of a battery module 50. That is, a CMU87 for monitoring the state of each of the plurality of battery cells 510 housed in the battery cell housing 500 is installed in the battery cell housing 500 housing the battery cells 510.

[0063] like Figure 3 As shown, in a battery pack 40, for example, when two battery modules 50 are housed in a housing 400, a structure using a shared BMU 85 is employed. That is, a BMU 85 is provided in the housing 400 to monitor and control the plurality of (e.g., two) battery modules 50 as a whole. In each battery module 50, a CMU 87 is provided in the battery cell housing 500 to monitor the plurality of battery cells 510 within that module. Therefore, even if the number of battery modules 50 housed in the battery pack 40 is changed, it is not necessary to change the BMU 85; only the configuration structure of the battery modules 50 needs to be changed.

[0064] For example, in the case of the battery pack 40 of this embodiment, the number of battery modules 50 housed in the housing 400 is two and they are of 48V specification. However, if it is changed to one and the voltage is changed to 24V specification, one of the two battery modules 50 can be removed from the housing 400. In addition, if three battery modules 50 of 72V specification are housed in one housing 400, if the size of the housing 400 is changed to accommodate three battery modules 50, it can be handled without significantly changing the design of BMU85.

[0065] (Battery module)

[0066] Figure 4 This is a partial exploded 3D view illustrating a battery module.

[0067] Figure 4 The image shows the state after a battery cell has been removed from the battery cell housing.

[0068] The battery cell housing 500 is formed of resin, for example. The battery cell housing 500 has a receiving portion 501 for accommodating battery cells 510 and a mounting portion 502 for mounting CMU87. The receiving portion 501 is configured as a box shape capable of accommodating a plurality of battery cells 510, and the mounting portion 502 is configured as a flat surface to facilitate mounting of the CMU87 substrate. In this embodiment, a plurality of battery cells 510 are arranged and stacked in the receiving portion 501.

[0069] The battery unit 510 is configured in a generally cuboid shape having a planar portion 510a and a bottom portion 510b facing each other, and four side portions 510c with an area smaller than both the planar portion 510a and the bottom portion 510b. Furthermore, the battery unit 510 is positioned such that the bottom portion 510b is adjacent to the bottom surface 400a of the housing 400 (see reference). Figure 3 The battery cells 510 are arranged opposite each other along the bottom surface 400a. Specifically, the bottom surface 510b of the battery cell 510 is arranged opposite to the bottom, i.e., the mounting surface 501a, of the inner side of the receiving portion 501 of the battery cell housing 500. When the battery cell housing 500 is housed in the housing 400, the mounting surface 501a of the receiving portion 501 is approximately parallel to the bottom surface 400a of the housing 400. Therefore, the bottom surface 510b of the battery cell 510 is arranged opposite to the bottom surface 400a of the housing 400. By mounting a plurality of battery cells 510 with their bottom surfaces 510b facing the mounting surface 501a, the battery module 50 can be made thinner.

[0070] exist Figure 4In the example shown, the battery units 510 are housed in a two-layer stacked configuration within the housing portion 501 of the battery unit housing 500. Five battery units 510 are arranged in the first layer, and four battery units 510 are arranged in the second layer. The outermost layer consists of only one battery unit 510, and a mounting portion 502 for placing the CMU87 is provided in the space above it, which serves as the second layer.

[0071] Figure 5 This is a three-dimensional diagram illustrating the connection of a plurality of battery cells.

[0072] Figure 5 It shows from and Figure 4 Observe from the opposite side Figure 4 A perspective view of a plurality of battery cells 510. For ease of explanation, in Figure 5 Battery cell housing 500 and CMU87 are omitted. For information on battery cell housing 500 and CMU87, please refer to [link / reference needed]. Figure 4 .

[0073] When an odd number (n) of battery cells 510 are accommodated in a battery cell housing 500, the battery cell housing 500 preferably accommodates: a first layer of battery cell group CG1, {(n+1) / 2} battery cells 510 along the bottom surface 400a of the housing 400 (refer to...). Figure 3 The first battery cell group CG2 is arranged in the direction of (n-1) / 2 in the first direction D1 and is stacked with the first battery cell group CG1 in the normal direction of the bottom surface 400a of the housing 400 (hereinafter referred to as "normal direction D3").

[0074] For example, such as Figure 5 As shown, with nine battery cells 510 housed in a battery cell housing 500, the cells are arranged in a two-layer stack, with the first layer designated as a first-layer battery cell group CG1 and the second layer as a second-layer battery cell group CG2. In the first-layer battery cell group CG1, five battery cells 510 are arranged in the first direction D1, and in the second-layer battery cell group CG2, four battery cells 510 are arranged in the first direction D1. These nine battery cells 510 are housed in the housing portion 501 of the battery cell housing 500.

[0075] CMU87 is positioned on the side of the first layer battery cell group CG1 closest to the second layer battery cell group CG2, and is arranged in a position aligned with the second layer battery cell group CG2 in the first direction D1. For example, in the case of nine battery cells 510, five battery cells 510 are arranged as the first layer battery cell group CG1, and four battery cells 510 are arranged as the second layer battery cell group CG2, stacked in the normal direction D3. Therefore, an empty space equivalent to one battery cell is formed in the arrangement of the second layer battery cell group CG2. This empty space is used as... Figure 4 The mounting portion 502 shown is where the CMU87 is configured. This allows for efficient use of the space in the battery module 50. Furthermore, this embodiment shows an example where an odd number of battery cells 510 are provided in a battery module 50, but an even number of battery cells 510 can also be provided.

[0076] like Figure 5 As shown, a positive electrode (+), a negative electrode (-), and a gas release valve V (battery cell valve) are provided on one of the side portions 510c of the cuboid-shaped battery cell 510. When multiple battery cells 510 are mounted and stacked, the side portions 510c with the positive electrode (+) and negative electrode (-) face the same side. At this time, in the first layer of battery cell group CG1 and the second layer of battery cell group CG2, the arrangement of the positive electrode (+) and negative electrode (-) of the battery cells 510 is reversed. That is, in the first layer of battery cell group CG1, the electrodes of the multiple battery cells 510 are arranged, for example, from one end in a first direction to the other in the order of positive electrode (+), negative electrode (-), positive electrode (+), negative electrode (-), ..., while in the second layer of battery cell group CG2, the battery cells 510 are arranged in the reverse order of negative electrode (-), positive electrode (+), negative electrode (-), positive electrode (+), ..., ...

[0077] Furthermore, the plurality of battery cells 510 constituting the first layer of battery cell group CG1 are connected by a first connecting busbar B1 in an arrangement order from one end of the first direction D1 to the other. Similarly, the plurality of battery cells 510 constituting the second layer of battery cell group CG2 are connected by a second connecting busbar B2 in an arrangement order from one end of the first direction D1 to the other. Then, the battery cells 510 disposed at the other end of the first layer of battery cell group CG1 and the battery cells 510 disposed at the other end of the second layer of battery cell group CG2 are connected by a third connecting busbar B3. Here, the busbar is a component formed from a sheet of metal (e.g., copper) in a predetermined shape. Furthermore, in this embodiment, a busbar is used as a component to connect adjacent battery cells 510 to each other, but wires other than busbars may also be used.

[0078] In the battery cells 510 (two battery cells 510 overlapping at the other end) configured at the other end of the first layer battery cell group CG1 and the second layer battery cell group CG2, since the polarity of the electrodes is arranged in the stacking direction as positive + and negative -, a plurality of battery cells 510 in the first layer battery cell group CG1 and the second layer battery cell group CG2 can be connected in series simply by installing the third connecting bus bar B3 in a straight position in the stacking direction.

[0079] Figure 6 This is a three-dimensional diagram illustrating the configuration of a plurality of battery modules.

[0080] Figure 7 This is a top view illustrating the configuration of multiple battery modules.

[0081] Here, in Figure 6 and Figure 7 In, to configure two Figure 5 Taking the battery module 50 shown as an example. For ease of explanation, in... Figure 6 Battery cell housing 500 and CMU87 are omitted. For information on battery cell housing 500 and CMU87, please refer to [link / reference needed]. Figure 4 .

[0082] When multiple battery modules 50 are configured, they can be installed along the housing 400 (refer to...). Figure 2 The bottom surface 400a (refer to) Figure 2 A plurality of battery modules 50 are arranged in a second direction (hereinafter referred to as "second direction D2") that intersects the first direction D1. Moreover, in this configuration of the plurality of battery modules 50, the battery cells 510 are arranged such that the positive electrode +, the negative electrode -, and the valve V are opposite to each other between adjacent battery modules 50.

[0083] Therefore, the first connecting busbar B1, the second connecting busbar B2, and the third connecting busbar B3 in each battery module 50 are arranged relative to each other between adjacent battery modules 50. By having the first connecting busbar B1, the second connecting busbar B2, and the third connecting busbar B3 in each battery module 50 relative to each other, it is easy to concentrate the conduction paths in multiple battery modules 50, thereby achieving space saving in the battery pack 40.

[0084] Furthermore, adjacent battery modules 50 in the second direction D2 are electrically connected to each other at one end in the first direction D1 by a fourth connecting busbar B4. In this case, it is preferable to arrange the two battery cells 510 connected by the fourth connecting busbar B4 on the same layer. Thus, the fourth connecting busbar B4 can be installed on the same layer.

[0085] To connect adjacent battery modules 50 in series and to arrange two battery cells 510 connected by the fourth connecting busbar B4 on the same layer, the positive + and negative - terminals of two opposing battery cells 510 (two opposing battery cells 510 along the second direction D2 between adjacent battery modules 50) are arranged in opposite directions among the plurality of battery cells 510 of adjacent battery modules 50. Thus, with the positive + and negative - terminals of the two battery cells 510 connected to the fourth connecting busbar B4 facing each other, a connection between their positive + and negative - terminals via the fourth connecting busbar B4 can be made with the shortest possible distance.

[0086] For example, the battery modules 50 on one side of two adjacent battery modules 50 are connected sequentially from the battery unit 510 at one end of the first direction D1 of the first layer battery unit group CG1 to the battery unit 510 at the other end by the first connecting bus bar B1. The battery units 510 of the first layer battery unit group CG1 and the battery units 510 of the second layer battery unit group CG2 at the other end are connected by the third connecting bus bar B3. The battery units 510 at the other end of the first direction of the second layer battery unit group CG2 are connected sequentially from the battery unit 510 at one end by the second connecting bus bar B2.

[0087] On the other hand, the battery modules 50 on the other side of the two adjacent battery modules 50 are opposite to the battery modules 50 on one side. The battery units 510 at one end of the first direction D1 of the second layer battery unit group CG2 are connected to the battery units 510 at the other end in sequence by the second connecting bus bar B2. The battery units 510 of the second layer battery unit group CG2 and the battery units 510 of the first layer battery unit group CG1 at the other end are connected by the third connecting bus bar B3. The battery units 510 at the other end of the first direction of the first layer battery unit group CG1 are connected to the battery units 510 at one end in sequence by the first connecting bus bar B1.

[0088] Furthermore, the battery cells 510 at one end of the second layer battery cell group CG2 of each of the two adjacent battery modules 50 in the first direction D1 are connected to each other by the fourth connecting bus bar B4.

[0089] That is, the connection structure formed by the first connecting busbar B1 to the fourth connecting busbar B4 is as follows: From one end of the first layer battery unit group CG1 on one side of two adjacent battery modules 50, it connects to the other end; after connecting to the second layer battery unit group CG2 at the other end, it returns to one end; the other end of the second layer battery unit group CG2 connects to the battery module 50 on the other side; from one end of the second layer battery unit group CG2, it connects to the other end; after connecting to the first layer battery unit group CG1 at the other end, it returns to one side. According to this connection structure, the shortest path connection can be achieved.

[0090] Additionally, the battery module 50 includes wiring (not shown) for transmitting information indicating the state (voltage, temperature) of the battery cell 510 to the CMU87. When multiple battery modules 50 are configured, this wiring is positioned between adjacent battery modules 50 for transmission to the CMU87. This allows for efficient utilization of the space between adjacent battery modules 50 to consolidate the wiring for transmission to the CMU87.

[0091] In addition, in each battery module 50, the valves V of each battery cell 510 are arranged opposite to each other between adjacent battery modules 50, thereby enabling the space between adjacent battery modules 50 to be used as a flow path for gas released from the valve.

[0092] Therefore, as Figure 3 As shown, when an exhaust valve 425 is provided on the housing cover 420 that opens when the internal pressure of the housing 400 reaches a predetermined pressure, it is preferable to position the exhaust valve 425 at a position overlapping with the adjacent battery module 50 when viewed along the normal direction (see figure). This allows gas released from the valve through the space between the adjacent battery modules 50 to be efficiently discharged from the exhaust valve 425.

[0093] Furthermore, the above describes an example where five battery cells 510 are arranged in the first layer battery cell group CG1, and four battery cells 510, one fewer than those in the first layer battery cell group CG1, are arranged in the second layer battery cell group CG2. However, the present invention is not limited to this. The number of battery cells 510 in the second layer battery cell group CG2 may be two or more fewer than that in the first layer battery cell group CG1, and the arrangement of the plurality of battery cells 510 in the second layer battery cell group CG1 may be non-contiguous. The mounting portion 502 (see reference 502) Figure 4 The position of ) may not be the end of the second layer battery cell group CG2.

[0094] (Single battery cell housing)

[0095] Figure 8 This is a top view illustrating a single battery cell housing.

[0096] A single battery cell housing 550 is a housing that accommodates one battery cell 510. The single battery cell housing 550 has a main body 551 for accommodating one battery cell 510 and a connecting portion 552 provided at the periphery of the main body 551. The main body 551 is configured as a box shape that internally accommodates one battery cell 510. The top view of the main body 551 is approximately rectangular (e.g., square). The connecting portion 552 is provided at each corner of the main body 551. Alternatively, the connecting portion 552 may be provided at the center of each side of the main body 551. The connecting portion 552 may also have holes for bolt fastening or an engaging portion based on a recess or protrusion.

[0097] Figure 9 This is a top view showing an example of the configuration of a single battery cell housing.

[0098] exist Figure 9 The example shown is a structure in which a plurality of individual battery cell housings 550 are connected longitudinally and transversely along a plane. A battery cell housing 500 is formed by connecting a plurality of individual battery cell housings 550. Individual battery cell housings 550 that are adjacent in both the longitudinal and transverse directions are connected to each other using connecting portions 552. Alternatively, a plurality of individual battery cell housings 550 can be connected longitudinally and transversely along the same plane, or they can be connected in either the longitudinal or transverse direction on the same plane. Furthermore, a plurality of individual battery cell housings 550 connected on the same plane can be stacked to form a multi-layer structure.

[0099] Figure 10 This is a perspective view showing a configuration example (second example) of a single battery cell housing.

[0100] exist Figure 10 In the example shown, a plurality of individual battery cell housings 550 are connected in an overlapping manner. A single battery cell housing 500 is formed by connecting the plurality of individual battery cell housings 550. Adjacent individual battery cell housings 550 in the stacking direction are connected to each other using connecting portions 552. Bolt-based fastening can also be performed by extending through the connecting portions 552 of all overlapping individual battery cell housings 550.

[0101] exist Figure 9 and Figure 10 In the connection of the plurality of individual battery cell housings 550 shown, by making the positive terminal + or negative terminal - of the battery cell 510 connected to the connection part 552, adjacent (or overlapping) individual battery cell housings 550 are connected to each other using the connection part 552, thereby the battery cells 510 of the plurality of individual battery cell housings 550 can also be connected in series or in parallel.

[0102] According to this embodiment, a battery pack 40 that can flexibly respond to specification changes can be provided.

[0103] (Another battery pack)

[0104] Next, we will describe the other battery pack.

[0105] In addition, the structural components of another battery pack 40 and Figures 2 to 10 Since the structural components of the battery pack 40 described herein are the same, repeated descriptions will be omitted as appropriate. The following description will focus on the differences.

[0106] Figure 11 This is a partial exploded perspective view illustrating another battery pack in this embodiment.

[0107] Figure 11 The diagram shows the battery pack 40's housing cover 420 and heat conduction member 600 with the housing 400 open.

[0108] Figure 12 This is a schematic cross-sectional view illustrating the battery pack of this embodiment.

[0109] Furthermore, the perspective view of another battery pack when viewed from an oblique angle is similar to... Figure 2 The appearance is the same as the 3D view shown.

[0110] The battery pack 40 includes: a battery module 50; a control circuit including BMU85 and CMU87; and a housing 400 housing the battery module 50 and the control circuit. The housing body 410 and the housing cover 420 are formed, for example, by casting an aluminum-containing metal material. A seal (not shown) is provided at the joint between the housing body 410 and the housing cover 420, thereby making the interior of the housing 400 watertight by covering the housing cover 420 onto the housing body 410 and fastening it, for example, with screws.

[0111] The battery module 50 housed in the housing 400 may have a plurality of battery cells 510. A single battery module 50 may be housed in a housing 400, or a plurality of battery modules 50 may be housed in the housing 400.

[0112] The battery unit 510 is configured in a generally cuboid shape having mutually opposing planar portions (upper surface portion 510a and bottom portion 510b) and four side portions 510c with an area smaller than both the upper surface portion 510a and the bottom portion 510b. Furthermore, the battery units 510 are arranged along the bottom surface 400a with the bottom portion 510b facing the bottom surface 400a of the housing 400.

[0113] The battery module 50 may also have a plurality of battery cells 510. In this case, the plurality of battery cells 510 are preferably arranged along the bottom surface 400a of the housing 400. Furthermore, the battery cells 510 may be arranged as a single layer or multiple layers within the housing 400. In the case of multiple layers, it is preferable that the upper surface portion 510a and the bottom portion 510b of two battery cells 510 are arranged opposite each other in the stacking direction.

[0114] An insulating heat-conducting member 600 is provided between the battery module 50 housed in the housing 400 and the housing 400. The heat-conducting member 600 is made of a material such as silicon wafer that has both insulating and thermal conductivity. The heat-conducting member 600 is disposed between the upper surface portion 510a of the battery cell 510 and the top surface 420a of the housing cover 420 (housing 400), which is opposite to the bottom surface 400a of the housing 400. The heat-conducting member 600 preferably contacts the upper surface portion 510a of the battery cell 510 and the top surface 420a of the housing cover 420, respectively. Alternatively, some kind of component may be sandwiched between the heat-conducting member 600 and the upper surface portion 510a, and between the heat-conducting member 600 and the top surface 420a.

[0115] The bottom surface 510b of the battery cell 510 is disposed opposite to the bottom surface 400a of the housing 400, so that the upper surface 510a of the battery cell 510 is opposite to the top surface 420a of the housing cover 420. In the battery cell 510, the area of ​​the upper surface 510a is larger than the area of ​​the side surface 510c. Therefore, through contact between the upper surface 510a and the heat conduction member 600 (including contact via the member), the heat generated in the battery cell 510 can be effectively transferred to the heat conduction member 600. In addition, through contact between the heat conduction member 600 and the top surface 420a of the housing cover 420 (including contact via the member), the heat transferred from the battery cell 510 to the heat conduction member 600 can be effectively transferred to the housing cover 420, thereby making it easier to release from the housing 400 to the outside.

[0116] The battery pack 40 may also have a plurality of battery modules 50. In this case, the plurality of battery modules 50 are preferably arranged along the bottom surface 400a of the housing 400. Thus, in the plurality of battery modules 50, since the upper surface portions 510a of the battery cells 510 do not overlap, it is advantageous in terms of heat dissipation.

[0117] In a structure in which a plurality of battery modules 50 are arranged, the heat conduction member 600 may also have a portion disposed between adjacent battery modules 50. By distributing a portion of the heat conduction member 600 between adjacent battery modules 50, heat can be easily transferred not only from the upper surface portion 510a of the battery cell 510 to the heat conduction member 600, but also from a portion of the side portion 510c to the heat conduction member 600.

[0118] Figure 13 This is a perspective view illustrating the top surface of the casing cover.

[0119] The housing cover 420 is formed, for example, by aluminum casting. The top surface 420a of the housing cover 420 has a junction with the battery module 50 (see reference). Figure 11 The first region A1 and the second region A2 are respectively located opposite to each other. In the housing cover 420, preferably, the surface roughness of the first region A1 is lower than that of the second region A2. For example, when the housing cover 420 is formed by casting, both the first region A1 and the second region A2 have relatively rough surface roughness due to the surface of the mold transferred by casting. Therefore, the first region A1 is machined or otherwise processed to make the surface roughness of the first region A1 lower than that of the second region A2. As a result, the fit between the first region A1 in the top surface 420a of the housing cover 420 and the heat conduction member 600 is improved, thereby enabling more efficient heat transfer from the heat conduction member 600 to the housing cover 420.

[0120] According to this embodiment, a battery pack 40 that can effectively release the heat of the battery cell 510 to the outside can be provided.

[0121] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. For example, a part of the structure of the above embodiments can be omitted, or it can be arbitrarily combined in a manner different from that described above.

[0122] Explanation of reference numerals in the attached figures: 1: Engine, 2: Electric generator, 10: Hybrid power system, 40: Battery pack, 50: Battery module, 51: Positive terminal, 52: Negative terminal, 65: Current detection unit, 67: Temperature detection unit, 70: DC / DC converter, 75: Positive side contactor, 76: Negative side contactor, 80: Battery, 81: Positive terminal, 82: Negative terminal, 85: BMU, 87: CMU, 100B: Ground, 150: ECU, 171: Positive wiring, 172: Negative wiring, 173: Positive wiring, 174: Positive wiring, 175: Negative wiring, 181: Signal line, 182: Signal line, 183: Signal line, 191: Signal line, 193: Signal line, 400: Housing, 400a: Bottom surface, 410: Housing body, 420: Housing cover, 420 a: Top surface; 425: Exhaust valve; 500: Battery cell housing; 500a: Fixing part; 501: Receiving part; 501a: Mounting surface; 502: Mounting part; 510: Battery cell; 510a: Upper surface (flat surface); 510b: Bottom surface (flat surface); 510c: Side surface; 550: Single battery cell housing; 551: Single battery cell housing body; 552: Connecting part; 600: Heat conduction component; A1: First region; B1: First connecting busbar; B2: Second connecting busbar; B3: Third connecting busbar; B4: Fourth connecting busbar; CG1: First layer of battery cell group; CG2: Second layer of battery cell group; D1: First direction; D2: Second direction; D3: Normal direction; R1: First cut-off signal; R2: Second cut-off signal; V: Valve

Claims

1. A battery pack, installed in a hybrid power system, wherein, have: The battery module supplies power to the electric generator of the hybrid power system; Control circuit, controlling the battery module; and A housing that accommodates the battery module and the control circuitry; The battery module has: Multiple battery cells; and A battery cell housing that accommodates a plurality of the battery cells; The control circuit has: The BMU (Battery Management Unit) monitors and controls the overall state of the battery pack; and The CMU (Cell Management Unit) monitors the status of each of the plurality of battery cells and sends information to the BMU; The CMU is installed in the battery cell housing of the battery module.

2. The battery pack according to claim 1, wherein, The battery cell housing has: a battery cell housing body; and a plurality of receiving portions disposed in the battery cell housing body and respectively accommodating one of the plurality of battery cells.

3. The battery pack according to claim 1, wherein, The battery cell housing has a plurality of individual housings that accommodate each of the plurality of battery cells.

4. The battery pack according to claim 1, wherein, A plurality of the battery cells are arranged along the bottom surface of the housing and stacked along the normal direction of the bottom surface.

5. The battery pack according to claim 1, wherein, All of the battery cells are arranged along the bottom surface of the housing.

6. The battery pack according to claim 1, wherein, Each of the plurality of battery cells is configured to have a generally cuboid shape having a planar portion and a bottom portion facing each other, and four side portions with an area smaller than both the planar portion and the bottom portion. The plurality of battery cells are arranged along the bottom surface with the bottom surface of the housing facing each other.

7. The battery pack according to claim 1, wherein, The battery module has n (n is an odd number) battery cells. The battery cell housing accommodates: The first layer of battery cells, {(n+1) / 2} battery cells are arranged in a first direction along the bottom surface of the housing; as well as The second layer of battery cells, {(n-1) / 2} battery cells are arranged in the first direction and are stacked with the first layer of battery cells in the normal direction of the bottom surface; The CMU is disposed on the side of the first layer of battery cells adjacent to the second layer of battery cells, and is disposed in a position that is aligned with the second layer of battery cells in the first direction.

8. The battery pack according to claim 7, wherein, The battery pack has a plurality of the battery modules. A plurality of the battery modules are arranged along the bottom surface and in a second direction intersecting the first direction.

9. The battery pack according to claim 8, wherein, The battery cell has a battery cell valve that opens when the pressure inside the battery cell exceeds a specified value. In a plurality of battery modules, the respective battery cell valves of the battery cells opposite each other are arranged opposite to each other.

10. The battery pack according to claim 9, wherein, The battery pack also has a venting valve disposed in the housing and opening when the internal pressure of the housing reaches a predetermined pressure. When viewed from the normal direction, the exhaust valve is positioned overlapping with adjacent battery modules among the plurality of battery modules.

11. The battery pack according to claim 8, wherein, The battery cell has a positive electrode terminal and a negative electrode terminal. In a plurality of battery modules, the electrode terminals of each of the battery cells are arranged opposite each other between adjacent battery modules.

12. The battery pack according to claim 11, wherein, Wiring is provided between adjacent battery modules in the plurality of battery modules to send information representing the state of each of the plurality of battery cells to the CMU.

13. The battery pack according to claim 7, wherein, The plurality of battery cells constituting the first layer of battery cell group are connected by a first connecting bus bar in an arrangement order from one end to the other in the first direction. The plurality of battery cells constituting the second layer of battery cells are connected by a second connecting busbar in an arrangement order from one end to the other end in the first direction. The battery cell located at the other end of the first layer of battery cell group and the battery cell located at the other end of the second layer of battery cell group are connected by a third connecting bus bar.

14. The battery pack according to claim 13, wherein, The battery pack has a plurality of the battery modules. A plurality of the battery modules are arranged relative to each other along the bottom surface and in a second direction intersecting the first direction. The adjacent battery modules in the second direction are connected to each other at one end by a fourth connecting bus bar.

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