Battery pack with improved rapid charging function

Abstract

A battery pack according to an embodiment of the present invention includes a first battery and a second battery, a connector unit including an electrode terminal and a communication terminal and configured to be connectable to an external device, and a BMS configured to determine whether the connector unit is connected to the external device and control an electrical connection relationship between the first battery, the second battery, and the external device according to the external device connected to the connector unit.

Description

Technical Field

[0001] The present invention relates to a battery pack, and more particularly, to a battery pack with improved rapid charging function.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0065676 filed on May 27, 2022, and all of the content disclosed in the specification and drawings of the said application is incorporated into this application.

Background Art

[0003] Recently, the demand for portable electronic products such as notebook PCs, video cameras, mobile phones, etc. has increased rapidly, and as the development of electric vehicles, energy storage batteries, robots, satellites, etc. has become full-scale, research on high-performance batteries capable of repeated charging and discharging has been actively underway.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these, lithium batteries have attracted attention for their advantages of almost no memory effect compared to nickel-based batteries, free charging and discharging, very low self-discharge rate, and high energy density.

[0005] In recent years, as the number of users of electric vehicles has increased, the demand for rapid charging of the batteries included in electric vehicles has been increasing. For example, in order to achieve rapid charging within 15 minutes, a current of 4C (C-rate) or more must be applied. However, since the batteries for electric vehicles in mass production are graphite-based batteries, there is a problem that lithium plating may occur when a high current of 4C or more is applied.

[0006] Here, lithium plating refers to the phenomenon in which lithium metal is deposited on the surface of the negative electrode. Lithium plating causes side reactions with the electrolyte and / or deformation of the kinetic balance of the battery, leading to battery degradation. In addition, since lithium metal deposition on the surface of the negative electrode can cause an internal short circuit in the battery, there are risks such as ignition and explosion due to the internal short circuit.

[0007] Therefore, there is a need to develop a battery pack that can prevent lithium plating and enable rapid charging.

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack with an improved rapid charging function.

[0009] Other objects and advantages of the present invention can be understood from the following description, and will be more clearly understood from the embodiments of the present invention. Also, the objects and advantages of the present invention can be realized by the means and combinations thereof shown in the claims.

Means for Solving the Problems

[0010] A battery pack according to an aspect of the present invention may include a first battery and a second battery, a connector portion including an electrode terminal and a communication terminal and configured to be connectable to an external device, and a BMS configured to determine whether the connector portion is connected to the external device and control the electrical connection relationship between the first battery, the second battery, and the external device according to the external device connected to the connector portion.

[0011] When a charger is connected to the connector part as the external device, the BMS may be configured to receive information related to the charging type from the charger and connect at least one of the first battery and the second battery to the charger according to the charging type.

[0012] When the charging type is slow charging, the BMS may be configured to connect the first battery and the second battery to the charger.

[0013] When the charging type is fast charging, the BMS may be configured to connect the second battery to the charger and disconnect the connection between the first battery and the charger.

[0014] After the fast charging of the second battery is completed, the BMS may be configured to change the charging type to slow charging and connect the first battery to the charger.

[0015] When a load is connected to the connector part as the external device, the BMS may be configured to connect the first battery to the load and disconnect the connection between the second battery and the load.

[0016] The BMS may be configured to measure the voltage of the first battery connected to the load and control the connection between the first battery, the second battery, and the load based on the voltage of the first battery.

[0017] When the voltage of the first battery is less than a preset critical voltage, the BMS may be configured to connect the second battery to the load and disconnect the connection between the first battery and the load.

[0018] The BMS may be configured to measure the voltage of the second battery and, when the voltages of the first battery and the second battery are the same, further connect the first battery to the load.

[0019] In addition, the battery pack according to another aspect of the present invention may further include a first relay connected between the first battery and the electrode terminal and configured to electrically connect or disconnect the first battery and the electrode terminal according to a controlled operating state, and a second relay connected between the second battery and the electrode terminal and configured to electrically connect or disconnect the second battery and the electrode terminal according to a controlled operating state.

[0020] The BMS may be configured to control the connection relationship between the first battery and the second battery and the external device by controlling the operating states of the first relay and the second relay.

[0021] The first battery and the second battery may be configured to have different negative electrode active materials.

[0022] An automobile according to still another aspect of the present invention may include the battery pack according to one aspect of the present invention.

Advantages of the Invention

[0023] According to one aspect of the present invention, there is an advantage that the occurrence of lithium plating can be prevented and a battery pack capable of rapid charging can be provided.

[0024] The effects of the present invention are not limited to the above-described effects, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention. Therefore, the present invention should not be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings. Instead, in accordance with the principle that the inventor can appropriately define the concept of the terms in order to explain the invention in the best way, they must be construed in accordance with the meanings and concepts corresponding to the technical idea of the present invention.

[0028] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Thus, there may be various equivalents and modifications that can replace them at the time of this application.

[0029] Also, when a specific description of a known function or configuration related to the present invention is determined to unnecessarily obscure the gist of the present invention, the description thereof will be omitted.

[0030] Terms including ordinal numbers such as first, second, etc. are used for the purpose of distinguishing any one of various components from the others, and the components are not limited by such terms.

[0031] Note that throughout the specification, when a certain part "includes" a certain component, unless otherwise specified, this does not mean excluding other components, but rather means that other components may further be included.

[0032] Furthermore, throughout the specification, when a certain part is "connected" to another part, this includes not only the case where it is "directly connected", but also the case where it is "indirectly connected" via other elements in between.

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] FIG. 1 is a diagram schematically showing a battery pack 100 according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing the configuration of the battery pack 100 according to an embodiment of the present invention.

[0035] Referring to FIG. 1, the battery pack 100 may include a first battery 110, a second battery 120, a connector portion 130, and a BMS (Battery Management System) 140.

[0036] Here, a battery means one independent cell having a negative electrode terminal and a positive electrode terminal and being physically separable. In one example, a lithium ion battery or a lithium polymer battery may be regarded as a battery. Also, a battery may mean a battery module in which a plurality of cells are connected in series and / or in parallel.

[0037] In the embodiment of FIG. 2, the battery pack 100 may be provided with a first battery 110 and a second battery 120. The positive electrode terminal of the first battery 110 and the positive electrode terminal of the second battery 120 may be connected to the positive electrode terminal P+ of the battery pack 100. And the negative electrode terminal of the first battery 110 and the negative electrode terminal of the second battery 120 may be connected to the negative electrode terminal P- of the battery pack 100.

[0038] The connector portion 130 includes electrode terminals P+, P- and a communication terminal CT, and may be configured to be connectable to an external device 200.

[0039] For example, the electrode terminals may include the positive electrode terminal P+ and the negative electrode terminal P- of the battery pack 100. The electrode terminals may be connected to the external device 200 to form a power line. And the communication terminal CT may form a communication line with the external device 200 connected to the battery pack 100.

[0040] In the embodiment of FIG. 2, the battery pack 100 can be connected to an external device 200. In this case, the electrode terminals can be connected to external electrode terminals provided in the external device 200. And the communication terminals can be connected to external communication terminals provided in the external device 200.

[0041] The BMS 140 can be configured to determine whether the connector unit 130 is connected to the external device 200.

[0042] For example, the BMS 140 can be connected to the communication terminal CT of the connector unit 130. And through a communication line formed by connecting the communication terminal CT of the connector unit 130 and the external communication terminal of the external device 200, the BMS 140 can communicate with the external device 200. That is, the BMS 140 can determine whether the connector unit 130 is connected to the external device 200 by communicating with the external device 200 through the communication line.

[0043] In another example, based on at least one change in voltage, current, and resistance of a power line formed by connecting the electrode terminals of the connector unit 130 and the external electrode terminals of the external device 200, the BMS 140 can determine whether the connector unit 130 is connected to the external device 200.

[0044] Desirably, the BMS 140 can determine not only whether the connector unit 130 is connected to the external device 200, but also the type of the external device 200 connected to the connector unit 130. For example, the BMS 140 can determine that the external device 200 connected to the connector unit 130 is a charger 210 or a load 220. Here, the charger 210 is a device that can apply a charging current to the battery pack 100 to charge the battery pack 100. And the load 220 is a device that can discharge the battery pack 100 by receiving a discharge current from the battery pack 100.

[0045] The BMS 140 can be configured to control the electrical connection relationship between the first battery 110 and the second battery 120 and the external device 200 according to the external device 200 connected to the connector unit 130.

[0046] Specifically, when an external device 200 is connected to the connector portion 130, the BMS 140 can control the electrical connection relationship between the first battery 110 and the second battery 120 and the external device 200 based on the type of the external device 200.

[0047] For example, the BMS 140 can connect the first battery 110 to the external device 200 and disconnect the connection between the second battery 120 and the external device 200. In the embodiment of FIG. 2, the BMS 140 can control the operating state of the first relay 150 to the on state and control the operating state of the second relay 160 to the off state.

[0048] In another example, the BMS 140 can connect the second battery 120 to the external device 200 and disconnect the connection between the first battery 110 and the external device 200. In the embodiment of FIG. 2, the BMS 140 can control the operating state of the first relay 150 to the off state and control the operating state of the second relay 160 to the on state.

[0049] That is, the BMS 140 has the advantage that the electrical connection relationship between the batteries 110 and 120 provided in the battery pack 100 and the external device 200 can be selectively configured based on whether the external device 200 is connected to the battery pack 100.

[0050] Referring further to FIG. 1, the battery pack 100 may further include a first relay 150 and a second relay 160.

[0051] The first relay 150 is connected between the first battery 110 and the electrode terminal and can be configured to electrically connect or disconnect the first battery 110 and the electrode terminal according to the controlled operating state.

[0052] In the embodiment of FIG. 2, when the operating state of the first relay 150 is the turned-on state, the first battery 110 and the external device 200 can be electrically connected. Conversely, when the operating state of the first relay 150 is the turned-off state, the electrical connection between the first battery 110 and the external device 200 can be interrupted.

[0053] The second relay 160 is connected between the second battery 120 and the electrode terminal, and can be configured to electrically connect or interrupt the second battery 120 and the electrode terminal according to the controlled operating state.

[0054] In the embodiment of FIG. 2, when the operating state of the second relay 160 is the turned-on state, the second battery 120 and the external device 200 can be electrically connected. Conversely, when the operating state of the second relay 160 is the turned-off state, the electrical connection between the second battery 120 and the external device 200 can be interrupted.

[0055] Note that the BMS 140 can be configured to control the connection relationship between the first battery 110 and the second battery 120 and the external device 200 by controlling the operating states of the first relay 150 and the second relay 160.

[0056] Specifically, the BMS 140 can control the operating states of the first relay 150 and the second relay 160 in consideration of the type of the external device 200 (for example, the charger 210 or the load 220) and the voltage of the first battery 110, etc.

[0057] On the other hand, the first battery 110 and the second battery 120 can be configured to have different negative electrode active materials.

[0058] Specifically, the first battery 110 can be a graphite-based battery, and the second battery 120 can be a silicon (Si)-based battery.

[0059] For example, the negative electrode active material of the first battery 110 can be 100% graphite, a mixture of graphite and a silicon compound (e.g., SiO and / or SiC), or a mixture of graphite and silicon.

[0060] For example, the negative electrode active material of the second battery 120 can be 100% silicon, a mixture of silicon and a silicon compound (e.g., SiO and / or SiC), or a mixture of silicon and graphite.

[0061] Here, when the negative electrode active materials of the first battery 110 and the second battery 120 are both mixtures of graphite and silicon, there can be a significant difference in the specific gravity of graphite in the negative electrode active material of the first battery 110 and that of the second battery 120. That is, the negative electrode active material of the first battery 110 can be a mixture of a large amount of graphite and a small amount of silicon. Conversely, the negative electrode active material of the second battery 120 can be a mixture of a large amount of silicon and a small amount of graphite.

[0062] Generally, when a charging current of 4C or more for rapid charging is applied to a graphite-based battery, there is a problem that the possibility of lithium plating significantly increases. On the other hand, a silicon-based battery has the advantage that the possibility of lithium plating is significantly lower than that of a graphite-based battery even when a charging current of 4C or more for rapid charging is applied. This is because the silicon-based battery has a high energy density and no directionality, so even when rapid charging is performed, the possibility of lithium plating is significantly lower than that of a graphite-based battery.

[0063] In contrast, since the graphite-based battery has much better life characteristics due to charging and discharging than the silicon-based battery, the silicon-based battery is not used alone. For example, when both the graphite-based battery and the silicon-based battery charge and discharge slowly, the deterioration of the graphite-based battery is less likely to progress than that of the silicon-based battery. This is because the silicon-based battery is more resistant to rapid charging than the graphite-based battery, but its life characteristics due to charging and discharging are not good.

[0064] Therefore, the battery pack 100 according to an embodiment of the present invention includes a graphite-based first battery 110 and a silicon-based second battery 120, which has the advantage of improving the rapid charging performance and life of the battery pack 100.

[0065] On the other hand, the BMS 140 may selectively include a processor, an ASIC (application-specific integrated circuit), other chip sets, logic circuits, registers, communication modems, data processing devices, etc., known in the art to execute various control logics performed in the present invention. Also, when the control logic is implemented as software, the BMS 140 may be implemented by a set of program modules. At this time, the program modules may be stored in the memory and executed by the BMS 140. The memory may exist inside or outside the BMS 140 and may be connected to the BMS 140 by various known means.

[0066] For example, the type of the memory is not particularly limited as long as it is a known information storage means capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory (registered trademark), ROM, EEPROM, registers, etc.

[0067] FIG. 3 is a diagram schematically showing the charging process of the battery pack 100 according to an embodiment of the present invention. FIGS. 4 and 5 are diagrams schematically showing an embodiment in which the battery pack 100 according to an embodiment of the present invention is slowly charged. FIGS. 6 to 8 are diagrams schematically showing an embodiment in which the battery pack 100 according to an embodiment of the present invention is rapidly charged.

[0068] Step S310 is a step of determining whether the connector unit 130 is connected to the charger 210, and can be performed by the BMS 140. In step S310, if the charger 210 is connected to the connector unit 130, the process proceeds to step S320, and if the charger 210 is not connected to the connector unit 130, step S310 can be further performed.

[0069] The BMS 140 can determine whether the connector unit 130 is connected to the charger 210 as the external device 200. And when the charger 210 as the external device 200 is connected to the connector unit 130, the BMS 140 can be configured to receive information related to the charging type from the charger 210.

[0070] Here, the charging type can be slow charging or rapid charging. Slow charging and rapid charging can be distinguished by a preset C-RATE. For example, for slow charging, the charging C-RATE is set with a target charging time of about 4 to 5 hours, and for rapid charging, the charging C-RATE can be set with a target charging time of about 15 to 30 minutes.

[0071] Specifically, when the charger 210 is connected to the connector unit 130, the BMS 140 and the charger 210 can communicate through the communication terminal CT of the connector unit 130. For example, the BMS 140 and the charger 210 can communicate using PLC (Power line communication) technology. The BMS 140 can receive information related to the charging type from the charger 210.

[0072] Step S320 is a step of determining the charging type of the charger 210 connected to the connector unit 130, and can be performed by the BMS 140. In step S320, if the charging type is slow charging, the process proceeds to step S330, and if the charging type is fast charging, the process may proceed to step S340.

[0073] Referring to steps S330 and S340, the BMS 140 may be configured to connect at least one of the first battery 110 and the second battery 120 to the charger 210 according to the charging type.

[0074] Specifically, the BMS 140 may be configured to select the first battery 110 and the second battery 120, or the second battery 120 as the battery to be charged according to the charging type. Then, the BMS 140 may be configured to connect the battery to be charged to the charger 210 and disconnect the connection between the charger 210 and the remaining unselected battery.

[0075] Step S330 is a step of connecting the first battery 110 and the second battery 120 to the charger 210 when the charging type is slow charging, and can be performed by the BMS 140.

[0076] Specifically, when the charging type is slow charging, the BMS 140 may be configured to connect both the first battery 110 and the second battery 120 to the charger 210. That is, when the charging type is slow charging, both the first battery 110 and the second battery 120 may be selected as the batteries to be charged.

[0077] For example, in the embodiment of FIG. 4, if the charging type of the charger 210 is slow charging, the charger 210 may be connected to the first battery 110 and the second battery 120.

[0078] For example, in the embodiment of FIG. 5, if the charging type of the charger 210 is slow charging, the BMS 140 may select the first battery 110 and the second battery 120 as the batteries to be charged. Then, the BMS 140 may control the operating state of the first relay 150 to the on state to connect the first battery 110 to the charger 210. And the BMS 140 may control the operating state of the second relay 160 to the on state to connect the second battery 120 to the charger 210.

[0079] That is, when the charging type is slow charging, since there is no risk of deterioration of the first battery 110 and the second battery 120 due to charging, the BMS 140 may control the operating states of both the first relay 150 and the second relay 160 to the on state. Therefore, it is possible for both the first battery 110 and the second battery 120 to be charged by the charger 210.

[0080] Step S340 is a step of connecting the second battery 120 to the charger 210 when the charging type is fast charging, and can be performed by the BMS 140. And the BMS 140 may disconnect the connection between the first battery 110 and the charger 210.

[0081] Specifically, when the charging type is fast charging, the BMS 140 may be configured to connect the second battery 120 to the charger 210 and disconnect the connection between the first battery 110 and the charger 210.

[0082] In the embodiment of FIG. 6, if the charging type of the charger 210 is fast charging, the charger 210 and the second battery 120 may be connected. Here, the connection between the first battery 110 and the charger 210 is in a disconnected state.

[0083] In the embodiment of FIG. 7, if the charging type of the charger 210 is fast charging, the BMS 140 may select the second battery 120 as the battery to be charged. Then, the BMS 140 may control the operating state of the second relay 160 to the on state to connect the second battery 120 to the charger 210. And the BMS 140 may control the operating state of the first relay 150 to the off state to disconnect the connection between the first battery 110 and the charger 210.

[0084] Step S350 is a step of connecting the first battery 110 and the charger 210, and may be performed by the BMS 140.

[0085] Specifically, the BMS 140 may be configured to change the charging type to slow charging after the fast charging of the second battery 120 is completed. For example, the BMS 140 may request the charger 210 to change the charging type via the communication terminal CT.

[0086] And the BMS 140 may connect the first battery 110 and the charger 210. Here, desirably, the BMS 140 may disconnect the connection between the second battery 120 and the charger 210.

[0087] For example, in the embodiment of FIG. 8, the second battery 120 for which the fast charging is completed is disconnected from the charger 210, and the first battery 110 for which the slow charging is required may be connected to the charger 210. That is, the BMS 140 may control the operating state of the second relay 160 to the off state and control the operating state of the first relay 150 to the on state.

[0088] Therefore, in the battery pack 100 according to an embodiment of the present invention, the second battery 120 that is resistant to rapid charging (less likely to deteriorate due to rapid charging) can be rapidly charged, and the first battery 110 that is weak in rapid charging (more likely to deteriorate due to rapid charging) can be slowly charged. That is, by the relay control by the BMS 140 included in the battery pack 100, all of the first battery 110 and the second battery 120 having different characteristics can be rapidly charged. Further, since deterioration of the first battery 110 is prevented during the charging process, as a result, there is an advantage that the life of the first battery 110 is increased.

[0089] FIGS. 9 to 11 are diagrams schematically showing an example in which the battery pack 100 according to an embodiment of the present invention is discharged. Specifically, FIG. 9 is a diagram schematically showing a discharging process of the battery pack 100. FIGS. 10 and 11 are diagrams schematically showing an exemplary configuration of the battery pack 100 during the discharging process.

[0090] Step S810 is a step of determining whether the connector unit 130 is connected to the load 220, and can be performed by the BMS 140. In step S810, if the load 220 is connected to the connector unit 130, the process proceeds to step S820. If the load 220 is not connected to the connector unit 130, step S810 can be further performed.

[0091] For example, in the embodiment of FIG. 10, the BMS 140 can be connected to the load 220 via the communication terminal CT. Then, the BMS 140 can determine whether the connector unit 130 is connected to the load 220 by communicating with the load 220.

[0092] Step S820 is a step in which the first battery 110 is connected to the load 220 when the load 220 is connected to the connector unit 130, and can be performed by the BMS 140.

[0093] Specifically, when a load 220 is connected to the connector part 130 as an external device 200, the BMS 140 may be configured to connect the first battery 110 and the load 220 and disconnect the connection between the second battery 120 and the load 220.

[0094] For example, in the embodiment of FIG. 10, the BMS 140 may control the operating state of the first relay 150 to the turn-on state in order to connect the first battery 110 to the load 220. Then, the BMS 140 may control the operating state of the second relay 160 to the turn-off state in order to disconnect the connection between the second battery 120 and the load 220.

[0095] Step S830 is a step of measuring the voltage of the first battery 110, and may be performed by the BMS 140.

[0096] Specifically, the BMS 140 may be configured to measure the voltage of the first battery 110. Then, the BMS 140 may be configured to control the connection between the first battery 110 and the second battery 120 and the load 220 based on the voltage of the first battery 110.

[0097] In the embodiment of FIG. 10, the BMS 140 may be connected to the first battery 110 and the second battery 120 via the sensing line SL. Then, the BMS 140 may measure the current, voltage, and temperature of the first battery 110 and the second battery 120 via the sensing line SL. In FIG. 10, the BMS 140 and the sensing line SL are schematically illustrated, but the measuring unit included in the BMS 140 (for example, including a voltage sensor, a current sensor, and a temperature sensor) may measure the current, voltage, and temperature of the first battery 110 and the second battery 120 via the sensing line SL.

[0098] Step S840 is a step of comparing the voltage of the first battery 110 with a critical voltage, and can be performed by the BMS 140. In step S840, if the voltage of the first battery 110 is less than the critical voltage, the process proceeds to step S850. If the voltage of the first battery 110 is greater than or equal to the critical voltage, step S830 can be further performed.

[0099] Here, the critical voltage is a voltage at which charging of the first battery 110 is required and can be preset. That is, the critical voltage can be preset to a voltage at which charging is required in order to prevent the first battery 110 from rapidly deteriorating. Such a critical voltage is set to correspond to the type of the first battery 110 and can be set theoretically or experimentally.

[0100] Step S850 is a step of connecting the second battery 120 and the load 220, and can be performed by the BMS 140.

[0101] Specifically, the BMS 140 can be configured to connect the second battery 120 and the load 220 when the voltage of the first battery 110 is less than a preset critical voltage. Desirably, the BMS 140 can be configured to disconnect the connection between the first battery 110 and the load 220 in order to prevent the first battery 110 from being further discharged.

[0102] For example, in the embodiment of FIG. 11, the BMS 140 can connect the load 220 and the second battery 120 by controlling the operating state of the second relay 160 to the on state. And the BMS 140 can disconnect the connection between the load 220 and the first battery 110 by controlling the operating state of the first relay 150 to the off state. In this case, since the first battery 110 is not further discharged, it is possible to prevent the deterioration of the first battery 110.

[0103] That is, the battery pack 100 according to an embodiment of the present invention can prevent deterioration of the first battery 110 due to discharge by controlling the electrical connection between the first battery 110, the second battery 120, and the load 220 according to the voltage of the first battery 110. Therefore, the lifespan of the first battery 110 can be increased.

[0104] FIGS. 12 and 13 schematically show other embodiments in which the battery pack according to an embodiment of the present invention discharges. Specifically, FIG. 12 schematically shows the discharge process of the battery pack 100. FIG. 13 schematically shows an exemplary configuration of the battery pack 100 during the discharge process. Here, the steps S860 to S880 in FIG. 12 can be performed after the step S850 in FIG. 9.

[0105] Step S860 can be performed after the step S850 in FIG. 9. Step S860 is a step of measuring the voltage of the second battery 120, and can be performed by the BMS 140.

[0106] For example, in FIG. 13, the BMS 140 can measure the voltage, current, and temperature of the second battery 120 via the sensing line SL.

[0107] Step S870 is a step of comparing the voltage of the first battery 110 with the voltage of the second battery 120, and can be performed by the BMS 140. If the voltage of the first battery 110 is the same as the voltage of the second battery 120 in step S870, the process proceeds to step S880; otherwise, step S860 can be performed.

[0108] Step S880 is a step of connecting the first battery 110 and the load 220, and can be performed by the BMS 140.

[0109] Specifically, when the voltage of the first battery 110 is the same as the voltage of the second battery 120, the BMS 140 may be further configured to connect the first battery 110 to the load 220. That is, when the voltages of both the first battery 110 and the second battery 120 correspond to the critical voltage, both the first battery 110 and the second battery 120 may be connected to the load 220.

[0110] For example, in the embodiment of FIG. 13, the BMS 140 may connect the first battery 110 to the load 220 by controlling the operating state of the first relay 150 to the turn-on state. That is, since the operating states of both the first relay 150 and the second relay 160 are in the turn-on state, the first battery 110 and the second battery 120 may be connected to the load 220 in a parallel structure.

[0111] Even if the voltage of the first battery 110 is different from the voltage of the second battery 120, if the BMS 140 controls the operating states of both the first relay 150 and the second relay 160 to the turn-on state, accidents such as heat generation, fire, or explosion may occur due to the difference in the rated capacities of the first battery 110 and the second battery 120. Therefore, the BMS 140 first disconnects the connection between the first battery 110 and the load 220 to prevent the deterioration of the first battery 110, and then, if the voltage of the second battery 120 becomes the same as the voltage of the first battery 110, the BMS 140 may further connect the first battery 110 to the load 220. Since both the first battery 110 and the second battery 120 are connected to the load 220, it is possible to smoothly supply power to the load 220.

[0112] FIG. 14 is a schematic diagram schematically showing the state of an automobile according to another embodiment of the present invention.

[0113] Referring to FIG. 14, the battery pack 100 according to an embodiment of the present invention may be included in a vehicle 10 such as an electric vehicle (EV) or a hybrid vehicle (HV). Then, the battery pack 100 can drive the vehicle 10 by supplying power to the motor by an inverter provided in the vehicle 10.

[0114] As described above, the present invention has been described with reference to limited embodiments and drawings. However, the present invention is not limited thereto, and various modifications and variations can be made by those having ordinary knowledge in the technical field to which the present invention pertains within the equivalent scope of the technical idea of the present invention and the following claims.

[0115] In addition, the present invention described above can be variously substituted, modified, and changed within the scope not departing from the technical idea of the present invention by those having ordinary knowledge in the technical field to which the present invention pertains. Therefore, the present invention is not limited by the above-described embodiments and the attached drawings, and it is possible to selectively combine all or part of each embodiment so that various modifications can be made.

Explanation of Reference Numerals

[0116] 10 Vehicle 100 Battery Pack 110 First Battery 120 Second Battery 130 Connector Unit 140 BMS 150 First Relay 160 Second Relay 200 External Device 210 Charger 220 Load

Claims

1. a first battery and a second battery; a connector unit including an electrode terminal and a communication terminal and configured to be connectable to an external device; a BMS configured to determine whether the connector unit is connected to the external device and control an electrical connection relationship between the first battery, the second battery, and the external device according to the external device connected to the connector unit; A battery pack, characterized by comprising the above.

2. The BMS is configured to receive information related to a charging type from the charger when the charger is connected to the connector unit as the external device, and connect at least one of the first battery and the second battery to the charger according to the charging type. The battery pack according to claim 1.

3. The BMS is configured to connect the first battery and the second battery to the charger when the charging type is slow charging. The battery pack according to claim 2.

4. The BMS is configured to connect the second battery to the charger and disconnect the connection between the first battery and the charger when the charging type is fast charging. The battery pack according to claim 2.

5. The BMS is configured to change the charging type to slow charging after the fast charging of the second battery is completed and connect the first battery to the charger. The battery pack according to claim 4.

6. The BMS is configured to connect the first battery to the load and disconnect the connection between the second battery and the load when the load is connected to the connector unit as the external device. The battery pack according to claim 1.

7. The BMS is configured to measure the voltage of the first battery connected to the load and control the connection between the first battery, the second battery, and the load based on the voltage of the first battery. The battery pack according to claim 6.

8. The BMS is When the voltage of the first battery is less than a preset critical voltage, the second battery and the load are connected, and the connection between the first battery and the load is cut off. The battery pack according to claim 7, characterized in that it is configured as such.

9. The BMS is configured to measure the voltage of the second battery, and when the voltages of the first battery and the second battery are the same, further connect the first battery to the load. The battery pack according to claim 8, characterized in that it is configured as such.

10. a first relay connected between the first battery and the electrode terminal and configured to electrically connect or disconnect the first battery and the electrode terminal according to a controlled operating state; a second relay connected between the second battery and the electrode terminal and configured to electrically connect or disconnect the second battery and the electrode terminal according to a controlled operating state; The battery pack according to claim 1, further comprising the above.

11. The BMS is configured to control the connection relationship between the first battery and the second battery and the external device by controlling the operating states of the first relay and the second relay. The battery pack according to claim 10, characterized in that it is configured as such.

12. The first battery and the second battery are configured to have different negative electrode active materials. The battery pack according to claim 1, characterized in that it is configured as such.

13. An automobile comprising the battery pack according to any one of claims 1 to 12.

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