Battery pack with energy dissipating resistor for preventing chain fire

Abstract

A battery pack according to the present disclosure includes: a plurality of battery modules arranged along at least one direction; a resistor connected to an abnormal battery module that is operating abnormally among the battery modules to absorb energy; an event detection unit configured to detect the abnormal battery module; a switch module that selectively forms a closed circuit by connecting or disconnecting each of the battery modules to the resistor; and a control unit that receives information from the event detection unit and controls the switch module to form a current path between the abnormal battery module and the resistor.

Description

Technical Field

[0001] The present disclosure relates to a battery pack having a device for preventing chain fire to adjacent modules when an event occurs in a specific module in the battery pack.

[0002] This application claims the benefit of Korean Patent Application No. 10-2019-0097677 filed on August 9, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Background Art

[0003] In contrast to non-rechargeable primary batteries, secondary batteries are rechargeable and are used as power sources not only for high-tech small electronic devices such as mobile phones, PDAs, and notebook computers, but also for energy storage systems (ESS), electric vehicles (EV), or hybrid electric vehicles (HEV).

[0004] Currently widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of a unit secondary battery cell or a unit battery cell is about 2.5V to 4.2V. Therefore, when a higher output voltage and energy capacity are required, a plurality of battery cells can be connected in series to construct a battery module, or two or more battery modules can be connected in series or in parallel and other components can be added to construct a battery pack. For example, a battery module may include a plurality of secondary batteries connected in series or in parallel, and a battery pack may include battery modules connected in series or in parallel to increase capacity and output.

[0005] Secondary batteries are charged and discharged through electrochemical reactions, and during charging and discharging, heat is generated. In this case, when the heat cannot be released well, degradation is accelerated, and in some cases, fire or explosion may occur. However, since the battery pack is an aggregate of battery modules, when a secondary battery fire or explosion occurs in a specific battery module, there is a high risk of chain fire or chain explosion in adjacent battery modules. In particular, automotive battery packs require safety devices because fire or explosion can cause personal injury.

[0006] Therefore, most battery packs include a cooling device to monitor the temperature of each battery module and maintain the temperature at an appropriate level, but there is no device for preventing a chain fire or chain explosion in an emergency. Summary of the invention

[0007] Technical issues

[0008] The present disclosure is designed to solve the above-mentioned problems, and thus aims to provide a battery pack having a safety device for preventing chain fire or chain explosion to adjacent battery modules when an event occurs in a specific battery module in the battery pack.

[0009] These and other purposes and advantages of the present disclosure can be understood through the following description, and will become apparent through the embodiments of the present disclosure. In addition, it will be easily understood that the purposes and advantages of the present disclosure can be achieved through the means in the claims and combinations thereof.

[0010] Technical Solution

[0011] According to one aspect of the present disclosure, a battery pack is provided, comprising: a plurality of battery modules arranged along at least one direction; a resistor, the resistor being connected to an abnormal battery module that is operating abnormally among the plurality of battery modules to absorb energy; an event detection unit configured to detect the abnormal battery module; a switch module, the switch module selectively forming a closed circuit by connecting or disconnecting each of the plurality of battery modules with the resistor; and a control unit, the control unit receiving information from the event detection unit and controlling the switch module to form a current path between the abnormal battery module and the resistor.

[0012] The battery pack may further include: a separator arranged alternately with the plurality of battery modules.

[0013] The spacer may be provided as a cooling plate having a channel through which cooling water flows, and the spacer is provided to contact at least one side surface of each battery module.

[0014] The resistor may be arranged in contact with one of the cooling plates.

[0015] The resistor may contact a cooling plate that contacts an outermost battery module that is located outermost in the arrangement order, and one surface of the cooling plate that contacts the outermost battery module contacts the outermost battery module, and another surface of the cooling plate that contacts the outermost battery module contacts the resistor.

[0016] The resistor may include a block having a surface contacting the cooling plate contacting the outermost battery module and a heating wire provided in the block.

[0017] The switch module may include switches each provided on a current path between a positive terminal of each battery module and one side of the resistor and on a current path between a negative terminal of each battery module and the other side of the resistor.

[0018] The control unit may be configured to electrically connect one of the abnormal battery modules to the resistor by selectively turning on some of the switches.

[0019] The control unit may be configured to electrically connect two or more of the abnormal battery modules to the resistor by selectively turning on some of the switches.

[0020] According to another aspect of the present disclosure, a vehicle including the battery pack is provided. The vehicle may include an electric vehicle (EV) or a hybrid electric vehicle (HEV).

[0021] Beneficial Effects

[0022] According to one aspect of the present disclosure, when an event is expected to occur in a specific battery module within a battery pack, chain fire or chain explosion to adjacent battery modules may be prevented by releasing energy of the corresponding battery module through a resistor.

[0023] According to another aspect of the present disclosure, under normal conditions, a partition with a cooling function can be used to cool the battery module. When an event occurs, the abnormal battery module can be prevented from generating heat, thereby preventing a chain fire or chain explosion of the battery module, and at the same time, the resistor can be cooled while consuming energy.

[0024] Other effects of the present disclosure can be understood through the following description and will be more clearly understood through the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a block diagram of a battery pack according to an embodiment of the present disclosure.

[0026] Figure 2 is a schematic diagram showing main components of a battery pack according to an embodiment of the present disclosure.

[0027] Figure 3 and Figure 4 is a circuit diagram illustrating a battery pack before and after energy consumption according to an embodiment of the present disclosure.

[0028] Figure 5 and Figure 6 is a circuit diagram illustrating a battery pack before and after energy consumption according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted on the basis of the meaning and concept corresponding to the technical aspects of the present disclosure based on the principle of allowing the inventor to appropriately define the terms for the best interpretation. Therefore, the embodiments described herein and the illustrations shown in the accompanying drawings are only some preferred embodiments of the present disclosure, and are not intended to fully describe the technical aspects of the present disclosure, so it should be understood that various other equivalents and modifications may be made to them when submitting this application.

[0030] Figure 1 is a block diagram of a battery pack according to an embodiment of the present disclosure, Figure 2 is a schematic diagram showing main components of a battery pack according to an embodiment of the present disclosure.

[0031] Reference Figure 1 and Figure 2 , a battery pack according to an embodiment of the present disclosure includes: a plurality of battery modules 10 , a resistor 20 , an event detection unit 30 , a switch module 40 , a control unit 50 , and a separator 60 .

[0032] Although not shown, the battery pack further includes a pack case accommodating the battery module 10 , and various types of devices that control charging and discharging of the battery module 10 , such as a battery management system (BMS), a current sensor, a fuse, and the like.

[0033] The battery modules 10 may be mounted in a battery pack housing and may be arranged adjacent to each other along at least one direction. Figure 2 , three battery modules 10 arranged in one direction are shown, but the battery modules 10 may be arranged in various arrangements, for example, in a 1×1 or 2×2 matrix arrangement, and the number of the battery modules 10 is not particularly limited.

[0034] Each battery module 10 includes a battery cell 11 and a module case 12 accommodating the battery cell 11. The battery cell 11 may include a pouch-type secondary battery cell.

[0035] like Figure 2As shown in , the pouch-type secondary battery cells may be stacked on top of each other and accommodated in the inner space of the module housing 12. In addition, the space between the inner wall of the module housing 12 and the two edges of the pouch-type secondary battery cells may be filled with a thermal interface material (TIM) 13. In this case, the TIM 13 may include a thermally conductive pad or resin having high thermal conductivity. The heat generated by the pouch-type secondary battery cells may be transferred to the separator 60 in contact with the module housing 12 through the TIM 13 and both sides of the module housing 12.

[0036] The partitions 60 and the battery modules 10 may be alternately arranged such that the partitions 60 are interposed between the battery modules 10. For example, the inner space of the battery pack case may be divided into a plurality of spaces by the partitions 60, and each battery module 10 may be installed in each space.

[0037] In this way, when each battery module 10 is placed in a space divided by the partition 60, even if an event occurs in a specific battery module 10, the partition 60 can prevent the event from affecting other battery modules 10, thereby minimizing damage (herein, situations in which the battery modules 10 are placed in an abnormal environment due to overheating, smoke, fire or explosion are collectively referred to as the occurrence of an event).

[0038] In the present disclosure, the partition 60 may be provided to divide the space where the battery modules 10 are installed and absorb heat from each battery module 10. For example, the partition 60 may be provided in the form of a cooling plate having a channel 61 therein and may serve as a heat sink to absorb heat of the battery modules 10.

[0039] Described in more detail, the partition 60 in the form of a cooling plate can be set in the form of a plate having a channel 61 for circulating cooling water and the size of the plate is equal to or larger than the size of the side of the battery module 10, and the cooling plate can contact one side of the battery module 10 to cool the battery module 10.

[0040] Although not shown, the cooling plate may further include a cooling water inlet and outlet extending to the inside / outside of the cooling plate and communicating with the channel 61 so that the cooling water circulates along the channel 61. The two ports may be connected to a cooling pipe installed inside / outside the battery pack to receive the cooling water.

[0041] As described above, in the present disclosure, a partition 60 in the form of a cooling plate can be inserted between the battery modules 10 to cool each battery module 10 under normal conditions, and when an incident occurs, the cooling plate can be used as a protective wall to block the flame or impact of the specific battery module 10 in which the incident occurs, so as to protect other battery modules 10.

[0042] On the other hand, as described above, the battery pack according to the present disclosure includes the resistor 20, the event detection unit 30, the switch module 40, and the control unit 50 to minimize the energy of the abnormal battery module 10 when an event occurs. This is to eliminate the risk of the event spreading to the surrounding battery modules 10 by quickly consuming the energy of the specific battery module 10 in which the event has occurred.

[0043] In the following, reference will be made to Figure 3 and Figure 4 Together with Figure 1 and Figure 2 An energy consumption system of a specific battery module 10 according to an embodiment of the present disclosure is described together in detail.

[0044] like Figure 2 and Figure 3 As shown in FIG. , each battery module 10 may be connected in parallel with one resistor 20 via a switch module 40 .

[0045] For reference, a plurality of resistors 20 corresponding to the number of battery modules 10 may be prepared, and each battery module 10 and each resistor 20 may be matched one-to-one, but as the number of resistors 20 increases, the energy density per unit volume of the battery pack decreases, the cost increases, and the burden of the assembly process increases. In addition, since the resistor 20 is configured to consume the energy of a specific battery module 10 that is in abnormal operation, it is not good to set a plurality of resistors 20 in the battery pack. Therefore, the present disclosure selectively forms a closed circuit with a specific battery module 10 by connecting or disconnecting one resistor 20 to each of the battery modules 10 through the switch module 40.

[0046] The event detection unit 30 is configured to detect a specific battery module 10 , that is, an abnormal battery module 10 in which an event occurs among the battery modules 10 , and may include a gas detection unit 31 and a temperature measurement unit 32 .

[0047] The gas detection unit 31 may include at least one gas sensor provided in each battery module 10. The gas sensor may include a combustible gas sensor, for example, a contact combustion sensor, a semiconductor sensor (Pd gate MOSFET), a ceramic gas sensor (ZnO, F2O3, SnO2, NiO, CoO), etc.

[0048] The temperature measuring unit 32 may include at least one temperature sensor provided in each battery module 10. The temperature sensor may include a contact type temperature sensor that measures heat by contacting the battery cell 11 or a non-contact type temperature sensor that measures heat radiated from the battery cell 11.

[0049] like Figure 3As shown in , the switch module 40 may include switches each disposed on a current path between a positive terminal of each battery module 10 and one side of the resistor 20 and on a current path between a negative terminal of each battery module 10 and the other side of the resistor 20 .

[0050] The switch remains in an off state under normal conditions and selectively operates in an on state only when an event occurs. For example, the switch may include a mechanical switch or an electronic relay switch.

[0051] The control unit 50 plays a role of receiving information from the event detection unit 30 and controlling the switch module 40 to form a current path between the abnormal battery module 10 and the resistor 20 .

[0052] The control unit 50 may be implemented using hardware of at least one of application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), microprocessors, or electronic units for performing other functions. The control unit 50 may include a memory.

[0053] The memory stores data, commands, and software required for the overall operation of the device, and the memory may include at least one of the following types of storage media: flash memory type, hard disk type, solid state disk (SSD) type, silicon disk drive (SDD) type, multimedia card micro type, random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), or programmable read-only memory (PROM).

[0054] Specifically, when an event occurs in a specific battery module 10 , an example of the operation of the consumption system is as follows.

[0055] For example, when an event occurs in the battery module M2, the gas sensor or the temperature sensor operates and sends a signal to the control unit 50. Figure 4 As shown in FIG, the control unit 50 controls the switches S2 and S3 to be in an on state and controls the switches S1 and S4 to be in an off state based on the signal, so that current flows between the specific battery module M2 and the resistor 20. Thus, the energy of the battery module M2 can be quickly consumed by the resistor 20.

[0056] In contrast, when an event is assumed to occur in the battery module M3 , the control unit 50 may control the switches S3 and S4 to be in an on state and the switches S1 and S2 to be in an off state to connect the battery module M3 to the resistor 20 in order to consume energy.

[0057] Furthermore, when an event is assumed to occur in the battery module M1 , the control unit 50 may control the switches S1 and S2 to an on state and the switches S3 and S4 to an off state to connect the battery module M1 to the resistor 20 in order to consume energy.

[0058] In addition, the heat energy generated by the resistor 20 during the energy consumption process can be released through the partition 60 in the form of the above-mentioned cooling plate.

[0059] To this end, the resistor 20 may include a block 21 having a surface contacting the cooling plate and a heating wire 22 disposed in the block 21. One side and the other side of the heating wire 22 may be connected to each battery module 10.

[0060] Return to reference Figure 2 , the resistor 20 may be arranged to contact the separator 60 in the form of a cooling plate that contacts the battery module 10 located at the outermost side in the arrangement order. Here, one surface of the cooling plate may be used to contact the right surface of the battery module 10, and the other surface of the cooling plate may be used to contact the resistor 20.

[0061] In this way, the present disclosure solves the problems of heat energy release of the resistor 20 and space-efficient installation of the resistor 20 at the same time by mounting the resistor 20 on the spacer 60 in the form of a cooling plate provided on the outer surface of the outermost battery module 10 .

[0062] Then, refer to Figure 5 and Figure 6 A battery pack according to another embodiment of the present disclosure is described.

[0063] A battery pack according to another embodiment of the present disclosure has substantially the same configuration as the battery pack according to the above-described embodiment, except for the configurations of the battery pack and the switch module 40. Descriptions of the same elements will be omitted.

[0064] The switch module 40 of the above-described embodiment is configured to connect one specific battery module 10 in which an event occurs to the resistor 20, while the switch module 40 of another embodiment of the present disclosure is configured to simultaneously cope with events occurring in two or more battery modules 10. In addition, the control unit 50 of the present embodiment is configured to control the switch module 40 to electrically connect at least one abnormal battery module 10 to the resistor 20 by selectively turning on some of the switches.

[0065] For example, the energy consumption circuit according to this embodiment may be as follows Figure 5 This can be achieved by giving Figure 3 The energy consumption circuit is realized by adding one more branch and switch between nodes a and c and between nodes b and d, and adding one more switch between nodes a and b. In addition, in the present embodiment, under normal conditions, switches S1 to S6 are set in the off state, and switch S7 is set in the on state.

[0066] According to the energy consumption circuit configuration, for example, when an event occurs in the battery module M2, the gas sensor or the temperature sensor operates and sends a signal to the control unit 50, and the control unit 50 controls the switches S2, S3, and S7 to be turned on based on the signal and controls all the remaining switches S1, S4, S5, and S6 to be turned off. In this case, the energy of the battery module M2 can be quickly consumed by the resistor 20.

[0067] When it is assumed that events occur simultaneously in battery modules M1 and M3, such as Figure 6 As shown in FIG. 2 , the control unit 50 controls the switches S2 , S3 , S4 to be in an on state and controls the switches S5 , S6 , and S7 to be in an off state to connect the battery modules M1 and M2 to the resistor 20 to consume their energy.

[0068] In addition, when it is assumed that an event occurs simultaneously in the battery modules M2 and M3, the control unit 50 can control the switches S4, S5, and S7 to be in the on state and all the remaining switches S1, S2, S3, and S6 to be in the off state to connect the battery modules M2 and M3 to the resistor 20 so as to consume their energy.

[0069] Therefore, the battery pack according to another embodiment of the present disclosure can cope with a situation where events occur simultaneously in a plurality of battery modules 10 , and thus is safer than the battery pack of the above-described embodiment.

[0070] The battery pack according to the present disclosure as described above can be applied to vehicles such as electric vehicles or hybrid vehicles. Of course, the battery pack can be applied to energy storage systems or other IT products.

[0071] Although preferred embodiments of the present disclosure have been shown and described above, the present disclosure is not limited to the specific preferred embodiments described above, and it is obvious to those skilled in the art that various modifications may be made to the present disclosure without departing from the subject matter of the present disclosure, and these modifications fall within the scope of the appended claims.

[0072] It should be noted that the terms indicating directions used herein, such as up, down, left, and right, are used only for convenience of description, and it is obvious to those skilled in the art that the terms may change depending on the position of the observer or the elements described.

Claims

1. A battery pack comprising: a plurality of battery modules arranged along at least one direction, the plurality of battery modules being connected in series with each other; a single resistor connected to an abnormal battery module that operates abnormally among the plurality of battery modules to absorb energy; an event detection unit configured to detect the abnormal battery module from among the plurality of battery modules; a switch module connected in parallel between the plurality of battery modules and the single resistor to selectively form a closed circuit by connecting or disconnecting each of the plurality of battery modules from the single resistor; and a control unit that receives information from the event detection unit and controls the switch module to form a current path only between the abnormal battery module and the single resistor, The plurality of battery modules include a first battery module (M3), a second battery module (M2) and a third battery module (M1) connected in series in sequence, a first node (a) is located between a negative terminal of the first battery module and a positive terminal of the second battery module, a second node (b) is located between a negative terminal of the second battery module and a positive terminal of the third battery module, a third node (c) is located on one side of the single resistor, and a fourth node (d) is located on the other side of the single resistor, The switch module includes a first switch (S4) arranged on the current path between the positive terminal of the first battery module and the third node, a second switch (S3) arranged on the current path between the first node and the fourth node, a third switch (S2) arranged on the current path between the second node and the third node, a fourth switch (S1) arranged on the current path between the negative terminal of the third battery module and the fourth node, a fifth switch (S6) arranged on the current path between the first node and the third node, a sixth switch (S5) arranged on the current path between the second node and the fourth node, and a seventh switch (S7) arranged on the current path between the first node and the second node.

2. The battery pack according to claim 1, further comprising: The partitions are arranged alternately with the plurality of battery modules. 3 . The battery pack according to claim 2 , wherein the separator is provided as a cooling plate having a channel through which cooling water flows, and the separator is provided to contact at least one side surface of each battery module. 4 . The battery pack according to claim 3 , wherein the single resistor is disposed in contact with one of the cooling plates.

5. The battery pack according to claim 3, wherein the single resistor contacts a cooling plate that contacts an outermost battery module located outermost in the arrangement order, and One surface of the cooling plate in contact with the outermost battery module is in contact with the outermost battery module, and the other surface of the cooling plate in contact with the outermost battery module is in contact with the single resistor. 6 . The battery pack according to claim 5 , wherein the single resistor comprises a block and a heating wire provided in the block, the block having a surface contacting the cooling plate contacting the outermost battery module. 7 . The battery pack according to claim 1 , wherein the control unit is configured to electrically connect one of the abnormal battery modules to the resistor by selectively turning on some of the switches. 8 . The battery pack according to claim 1 , wherein the control unit is configured to electrically connect two or more of the abnormal battery modules to the resistor by selectively turning on some of the switches.

9. A vehicle comprising the battery pack according to any one of claims 1 to 8.

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